The Develocity Maven extension improves your development workflow and your productivity, when developing and maintaining Apache Maven™ builds. The extension enables Build Scan insights, Build Cache acceleration, Predictive Test Selection, and Test Distribution.

Getting set up

Automated setup

(Maven extension 1.19+)

Execute the init goal to quickly set up the Develocity Maven extension on a Maven project:

mvn com.gradle:gradle-enterprise-maven-extension:1.20.1:init -Dgradle.enterprise.url=https://develocity.mycompany.com

See here for more information.

Manual setup

Apply the Develocity Maven extension to your build by adding the following configuration block to a new or existing .mvn/extensions.xml file in your Maven project. Maven automatically downloads the extension from Maven Central when you run your build.

Add the following to .mvn/extensions.xml
<extensions>
  <extension>
    <groupId>com.gradle</groupId>
    <artifactId>gradle-enterprise-maven-extension</artifactId>
    <version>1.20.1</version>
  </extension>
</extensions>

You can also add the extension jar into the lib/ext folder of your Maven installation. This is useful if you are packaging a custom Maven installation for your organization and you want Develocity to be available to all your projects out of the box.

The extension is configured through one or more gradle-enterprise.xml files and the pluginManagement sections of your pom.xml files. Similarly to the extensions.xml file, the gradle-enterprise.xml file can be placed in your Maven project’s .mvn directory. Unless you intend to publish build scans to scans.gradle.com, the minimum configuration required is the Develocity server URL.

Add the following to .mvn/gradle-enterprise.xml
<gradleEnterprise>
  <server>
    <url>https://gradle-enterprise.mycompany.com</url>
  </server>
</gradleEnterprise>

Other mechanisms for configuring Develocity are available, including alternate file locations for gradle-enterprise.xml and programmatic configuration with a custom Maven extension. For the full reference of the extension’s configuration, see the configuration reference. All available configuration options will be introduced over the coming sections.

Since version 1.2, the Develocity Maven extension captures an identifier used to uniquely represent a given workspace.

  • For versions 1.2.3+, this identifier is stored under .mvn/.gradle-enterprise/gradle-enterprise-workspace-id. The .mvn/.gradle-enterprise folder should NOT be committed under version control.

  • For versions [1.2 - 1.2.2], the identifier is stored under .mvn/gradle-enterprise-workspace-id.txt. The file is migrated to the new location when upgrading to a Develocity Maven extension version that is at least 1.2.3. The .mvn/gradle-enterprise-workspace-id.txt file should NOT be committed under version control.

Using build scans

Build scans are a record of what happened during a build, captured and visualized by Develocity.

Build scans are an important tool for developing and maintaining Maven builds. They provide insights into exactly what your builds are doing, helping you identify problems with the build environment, performance, and more. They can also help you understand and improve the build more generally, and make collaborating with others easier.

build scan service overview
Figure 1. build scans can be published to Develocity or scans.gradle.com

Develocity is a commercial product for companies that can be hosted on their own systems and ships with a build scan server and a Build Cache backend implementation. scans.gradle.com is a build scan server available for free, hosted by Gradle Inc.

There are two aspects to working with build scans:

  • Data collection

  • Publishing

Enabling publication of build scans

Enabling publication of build scans depends on whether you are publishing to a Develocity instance or scans.gradle.com. In the case of Develocity, you need to specify the server’s location. In the case of scans.gradle.com, you need to accept the terms of service.

Set the location of your Develocity instance

When you publish build scans to a Develocity instance, you must configure the location of the Develocity server.

gradleEnterprise.setServer("https://gradle-enterprise.mycompany.com");
$ mvn package -Dgradle.enterprise.url=https://develocity.mycompany.com
Add the following to gradle-enterprise.xml
<gradleEnterprise>
  <server>
    <url>https://gradle-enterprise.mycompany.com</url>
  </server>
</gradleEnterprise>

The precise URL you need depends on the hostname that your Develocity instance has been configured with. If in doubt, be sure to ask whomever manages that instance.

You may encounter a warning about an untrusted certificate when connecting to Develocity over HTTPS. The ideal solution is for someone to add a valid SSL certificate to the Develocity instance, but we recognise that you may not be able to do that. In this case, set the allowUntrustedServer option to true:

gradleEnterprise.setAllowUntrustedServer(true);
$ mvn package -Dgradle.enterprise.allowUntrustedServer=true
Add the following to gradle-enterprise.xml
<gradleEnterprise>
  <server>
    <allowUntrusted>true</allowUntrusted>
  </server>
</gradleEnterprise>
This is a convenient workaround during the initial evaluation, but it is a serious security issue and should not be used in production.

Accept the scans.gradle.com terms of service

In order to publish to scans.gradle.com, you need to accept the terms of service.

buildScan.setTermsOfServiceUrl("https://gradle.com/terms-of-service");
buildScan.setTermsOfServiceAgree("true");
$ mvn package -Dgradle.scan.termsOfService.url=https://gradle.com/terms-of-service -Dgradle.scan.termsOfService.accept=true
Add the following to gradle-enterprise.xml
<gradleEnterprise>
  <buildScan>
    <termsOfService>
      <url>https://gradle.com/terms-of-service</url>
      <accept>true</accept>
    </termsOfService>
  </buildScan>
</gradleEnterprise>

Be sure to check the terms of service at the URL shown in the above fragment.

Once you have accepted the terms of service, you can start publishing build scans to scans.gradle.com.

If you don’t accept the terms of service, as explained above, you will be prompted to agree to the terms of service on the command line, before any attempt of publishing a build scan. This can be useful if you share your gradle-enterprise.xml file with others, and you want everyone to explicitly accept those terms of service.

Integrating your CI tool

Jenkins

The Gradle Jenkins plugin prominently displays links to the Build Scan for any Gradle or Maven build that produce build scans, which makes it convenient to access the build scans. See the following screenshot for an example:

jenkins

Besides that, the plugin allows you to instrument all CI jobs and to publish a Build Scan without modifying the underlying projects. This eases the adoption of build scans within the company and allows configuring the Develocity Gradle plugin or Develocity Maven extension in a central place. For more information please read the documentation here.

TeamCity

The TeamCity Build Scan plugin prominently displays links to the Build Scan for any Gradle or Maven build that produce build scans, which makes it convenient to access the build scans. See the following screenshot for an example:

teamcity

Besides that, the plugin allows you to instrument all CI jobs and to publish a Build Scan without modifying the underlying projects. This eases the adoption of build scans within the company and allows configuring the Develocity Gradle plugin or Develocity Maven extension in a central place. For more information please read the documentation here.

Bamboo

The Develocity Bamboo plugin prominently displays links to the Build Scan for any Gradle or Maven build that produce build scans, which makes it convenient to access the build scans. See the following screenshot for an example:

bamboo

Besides that, the plugin allows you to instrument all CI jobs and to publish a Build Scan without modifying the underlying projects. This eases the adoption of build scans within the company and allows configuring the Develocity Gradle plugin or Develocity Maven extension in a central place. For more information please read the documentation here.

GitLab templates

The Develocity GitLab templates allow you to instrument CI jobs and to publish a Build Scan without modifying the project’s build scripts. This eases the adoption of build scans within the company and allows configuring the Develocity Gradle plugin or Develocity Maven extension at the CI level. For more information please read the documentation here.

Controlling when build scans are published

Once you’ve gone through the initial setup of the previous section, you are ready to start publishing build scans. But when should you publish them? Every time you run a build? Only when the build fails? It’s up to you. The Develocity Maven extension has several options that allow you to use whatever approach works best.

Publishing every build run

This is the default. There are many advantages to publishing build scans regularly, such as being able to track the behavior and performance of a build over time. It makes no sense relying on ad-hoc publishing of scans in such a situation as it’s easy to forget on the command line. Should you decide to explicitly enforce this default option, you can do this as follows:

buildScan.publishAlways();
Always publishing a build scan cannot be done via command-line argument.
Add the following to gradle-enterprise.xml
<gradleEnterprise>
  <buildScan>
    <publish>ALWAYS</publish>
  </buildScan>
</gradleEnterprise>

This approach means that you get a build scan for every successful and failed build that runs, including from your continuous integration infrastructure and your developers.

If you want to deactivate build scans for a particular build, you can pass the -Dscan=false system property to Maven.

Publishing on demand

We imagine that when you first start experimenting with build scans, you won’t want to publish them all the time until you become familiar with the implications. Even then, you may have good reason not to go all-in and automate the process. That’s where one-off build scans come in.

If you only want to publish build scans when explicitly requested, use the following option:

buildScan.publishOnDemand();
Pass the scan system property to Maven
$ mvn clean verify -Dscan
Add the following to gradle-enterprise.xml
<gradleEnterprise>
  <buildScan>
    <publish>ON_DEMAND</publish>
  </buildScan>
</gradleEnterprise>

When using Develocity Maven extension 1.16 or above, you can also publish a build scan for the most recently run build by invoking the build-scan-publish-previous goal.

No build scan is produced at the end of the build
$ mvn clean verify --offline
The build scan from the previous invocation is published
$ mvn gradle-enterprise:build-scan-publish-previous

Publishing based on criteria

Many of you will want a bit more control over exactly when build scans are published without resorting to using -Dscan each time. Perhaps you only want to publish build scans when the build fails, or if the build is running on your continuous integration infrastructure. Such scenarios are covered by the options in the following table.

buildScan.publishAlwaysIf(true);    // Publish a build scan if the given condition is true, regardless of whether the build succeeds or fails
buildScan.publishOnFailure();       // Publish a build scan only when the build fails
buildScan.publishOnFailureIf(true); // Publish a build scan only if the condition is true and the build fails
Conditional publication is not available via command-line argument.
Add the following to gradle-enterprise.xml
<gradleEnterprise>
  <buildScan>
    <publish>ON_FAILURE</publish>
  </buildScan>
</gradleEnterprise>

Giving a more concrete example, let’s say you only want to publish build scans from your CI system, which is identified by having a CI environment variable. This configuration will do the trick:

buildScan.publishAlwaysIf(System.getenv("CI") != null);
Conditional publication is not available via command-line argument.
<gradleEnterprise>
  <buildScan>
    <publish>#{env['CI'] == null ? 'ON_DEMAND' : 'ALWAYS'}</publish>
  </buildScan>
</gradleEnterprise>

Configuring background uploading

(Maven extension 1.5+, Develocity 2020.2+)

By default, build scans are uploaded in the background after the build has finished. This allows the build to finish sooner, but can be problematic in build environments (e.g. ephemeral CI agents) that terminate as soon as the build is finished, as the upload may be terminated before it completes. Background uploading should be disabled for such environments.

Prior to version 1.5 of the Maven extension, build scans are always uploaded before the build finishes.

Background build scan upload can be disabled programmatically, via a system property, or via the gradle-enterprise.xml configuration file.

buildScan.setUploadInBackground(false);
Add the gradle.scan.uploadInBackground system property to Maven
$ mvn clean verify -Dgradle.scan.uploadInBackground=false
Add the following to gradle-enterprise.xml
<gradleEnterprise>
  <buildScan>
    <backgroundBuildScanUpload>false</backgroundBuildScanUpload>
  </buildScan>
</gradleEnterprise>

It may be desirable to conditionally set the value based on the environment.

buildScan.setUploadInBackground(System.getenv("CI") == null);
Add the gradle.scan.uploadInBackground system property only on the CI build configuration
$ mvn clean verify -Dgradle.scan.uploadInBackground=false
<gradleEnterprise>
  <buildScan>
    <backgroundBuildScanUpload>#{env['CI'] == null}</backgroundBuildScanUpload>
  </buildScan>
</gradleEnterprise>

Configuring project identifier

(Maven extension 1.19+, Develocity 2023.3+)

Detailed information regarding project-level access control can be found here.

Versions before 1.19 of this extension do not allow specifying project identifier

Project identifier can be set programmatically, via a system property, or via the gradle-enterprise.xml configuration file.

gradleEnterprise.setProjectId("myProject");
Add the gradle.enterprise.projectId system property to Maven
$ mvn clean verify -Dgradle.enterprise.projectId=myProject
Add the following to gradle-enterprise.xml
<gradleEnterprise>
  <projectId>myProject</projectId>
</gradleEnterprise>

Authenticating with Develocity

(Maven extension 1.3+, Develocity 2019.4+)

Develocity installations may be configured to require build scan publishing to be authenticated. Additionally, installations may be configured to only allow certain users to publish build scans.

Develocity access keys should be treated with the same secrecy as passwords. They are used to authorize access to Develocity from a build.

Automated access key provisioning

The easiest way to configure a build environment to authenticate with Develocity is to use the following goal:

$ mvn gradle-enterprise:provision-access-key

When executed, it opens your web browser and asks to confirm provisioning of a new access key. You will be asked to sign in to Develocity in your browser first if you are not already signed in.

When confirmed, a new access key will be generated and stored in the .gradle-enterprise/keys.properties file within the Maven user home directory (~/.m2 by default).

Any existing access key for the same server will be replaced in the file, but will not be revoked at the server for use elsewhere. To revoke old access keys, sign in to Develocity and access “My settings” via the user menu at the top right of the page.

If your browser cannot be opened automatically at the correct page, you will be asked to manually open a link provided in the build console.

Manual access key configuration

Access keys can also be configured manually for an environment, when automated provisioning is not suitable.

Creating access keys

To create a new access key, sign in to Develocity and access “My settings” via the user menu at the top right of the page. From there, use the “Access keys” section to generate an access key.

The access key value should then be copied and configured in your build environment via file or via environment variable.

Via file

Develocity access keys are stored inside the Maven user home directory (~/.m2 by default), at .gradle-enterprise/keys.properties, in a Java properties file. The property name refers to the host name of the server, and the value is the access key.

gradle-enterprise.mycompany.com=7w5kbqqjea4vonghohvuyra5bnvszop4asbqee3m3sm6dbjdudtq

The file may contain multiple entries. The first entry for a given host value will be used.

Via environment variable

The access key may also be specified via the GRADLE_ENTERPRISE_ACCESS_KEY environment variable. This is typically more suitable for CI build environments.

The environment variable value format is «server host name»=«access key».

$ export GRADLE_ENTERPRISE_ACCESS_KEY=gradle-enterprise.mycompany.com=7w5kbqqjea4vonghohvuyra5bnvszop4asbqee3m3sm6dbjdudtq && \
  mvn package

The server host name is specified in order to prevent the access key being transmitted to a different server than intended. In the rare case that you require access keys for multiple servers, you can specify multiple entries separated by semicolons (requires Maven extension 1.9+, Develocity 2021.1+).

$ export GRADLE_ENTERPRISE_ACCESS_KEY=ge1.mycompany.com=7w5kbqqjea4vonghohvuyra5bnvszop4asbqee3m3sm6dbjdudtq;ge2.mycompany.com=9y4agfiubqqjea4vonghohvuyra5bnvszop4asbqee3m3sm67w5k && \
  mvn package
Via configuration

(Maven extension 1.11+)

The accessKey can also be set via the extension’s configuration.

gradleEnterprise.setServer("https://gradle-enterprise.mycompany.com");
gradleEnterprise.setAccessKey("7w5kbqqjea4vonghohvuyra5bnvszop4asbqee3m3sm6dbjdudtq");
The access key cannot be set via command-line argument.
Add the following to gradle-enterprise.xml
<gradleEnterprise>
  <server>
    <url>https://gradle-enterprise.mycompany.com</url>
    <accessKey>7w5kbqqjea4vonghohvuyra5bnvszop4asbqee3m3sm6dbjdudtq</accessKey>
  </server>
</gradleEnterprise>

An access key configured for the server this way will take precedence over an access key set via the environment variable or access key file.

Capturing goal input files

(Maven extension v1.1+)

Build scans capture hashes of goal inputs, to enable identifying changes to inputs when comparing builds, among other features. By default, an overall hash value for each goal input property is captured. This enables identifying which properties changed for a goal execution (e.g. the source or the classpath for Java compilation), but not which individual files changed. In order to identify file changes, the paths and content hashes of each individual input file must be captured, which can be enabled.

When to enable

Capturing goal input files increases the amount of data transmitted to the build scan server at the end of the build. If the network connection to the build scan server is poor, it may increase the time required to transmit. Additionally, it may also increase the data storage requirements for the build scan server.

This data is used for build comparison and Predictive Test Selection, which both are only available in Develocity. If you are using scans.gradle.com, it is not recommended that you enable capture of goal input files.

If you are using Develocity and utilising its Build Cache to accelerate your builds, it is strongly recommended to enable capture of goal input files as identifying which files have changed between builds with build comparison is extremely effective for diagnosing unexpected Build Cache misses.

If you are using Develocity for Predictive Test Selection enabling capture of goal input files is a prerequisite.

How to enable

Goal input files capture can be enabled programmatically, via a system property, or via the gradle-enterprise.xml configuration file.

buildScan.setCaptureGoalInputFiles(true);       // for extension < 1.11
buildScan.getCapture().setGoalInputFiles(true); // for extension >= 1.11
Add the gradle.scan.captureGoalInputFiles system property to Maven
$ mvn clean verify -Dgradle.scan.captureGoalInputFiles=true
Add the following to gradle-enterprise.xml
<gradleEnterprise>
  <buildScan>
    <captureGoalInputFiles>true</captureGoalInputFiles> <!-- For extension < 1.11-->
    <capture>                                           <!-- For extension >= 1.11 -->
      <goalInputFiles>true</goalInputFiles>
    </capture>
  </buildScan>
</gradleEnterprise>

Capturing build and test outputs

(Maven extension v1.11+)

By default, outputs generated during the build are captured and displayed in build scans.

Note that when disabling test output capturing, test failures will still be captured.

When to disable

You may want to skip capturing build or test outputs for security/privacy reasons (i.e., some outputs may leak sensitive data), or performance/storage reasons (i.e., some goals/tests may produce a lot of outputs that are irrelevant for your usage of build scans).

How to disable

Output capture can be disabled programmatically, via a system property, or via the gradle-enterprise.xml configuration file.

buildScan.getCapture().setBuildLogging(false);
buildScan.getCapture().setTestLogging(false);
Add the gradle.scan.captureBuildLogging and gradle.scan.captureTestLogging system properties to Maven
$ mvn clean verify -Dgradle.scan.captureBuildLogging=false -Dgradle.scan.captureTestLogging=false
Add the following to gradle-enterprise.xml
<gradleEnterprise>
  <buildScan>
    <capture>
      <buildLogging>false</buildLogging>
      <testLogging>false</testLogging>
    </capture>
  </buildScan>
</gradleEnterprise>

Extending build scans

You can easily include extra custom information in your build scans in the form of tags, links and values. This is a very powerful mechanism for capturing and sharing information that is important to your build and development process.

This information can be anything you like. You can tag all builds run by your continuous integration tool with a CI tag. You can capture the name of the environment that the build published to as a value. You can link to the source revision for the build in an online tool such as GitHub. The possibilities are endless.

You can see how the custom data appears in figures 2 and 3:

scan with custom data 1
Figure 2. A build scan containing tags and links
scan with custom data 2
Figure 3. A build scan containing custom values

Develocity allows listing and searching across all of the build scans in the system. You can find and filter build scans by tags and custom values, in addition to project name, outcome and other properties. In figure 4, for example, we are filtering for all Maven build scans that have the tag "CI" and a git branch name of "release":

build scan filtered list
Figure 4. A filtered list of build scans in Develocity

Adding tags

Tags are typically used to indicate the type or class of a build, or a key characteristic. They are prominent in the user interface and quickly inform a user about the nature of a build. A build can have zero or more tags.

buildScan.tag("my tag");
Add the scan.tag.<tag> system property to Maven
$ mvn package -Dscan.tag.CI
Add the following to gradle-enterprise.xml
<gradleEnterprise>
  <buildScan>
    <tags>
      <tag>my tag</tag>
    </tags>
  </buildScan>
</gradleEnterprise>
Add the following to a project pom.xml
<project>
  <!-- other build configuration -->
  <pluginManagement>
  <plugins>
    <plugin>
      <groupId>com.gradle</groupId>
      <artifactId>gradle-enterprise-maven-extension</artifactId>
      <configuration>
        <gradleEnterprise>
          <buildScan>
            <tags>
              <tag>my tag</tag>
            </tags>
          </buildScan>
        </gradleEnterprise>
      </configuration>
    </plugin>
  </plugins>
  </pluginManagement>
</project>

Prefer the programmatic access. If specified in parent POM, tags will be applied to all projects inheriting from it.

Note that the order in which you declare the tags doesn’t affect the build scan view. They are displayed in alphabetical order, with any all-caps labels displayed before the rest.

You can see the effect of a custom tag in figure 2.

The Develocity Maven extension imposes limits on captured tags:

  • maximum tag count: 50

  • maximum tag length: 200 characters

Builds rarely live in isolation. Where does the project source live? Is there online documentation for the project? Where can you find the project’s issue tracker? If these exist and have a URL, you can add them to the build scan.

buildScan.link("my link", "http://my-site.com");
Add the scan.link.<name>=<URL> system property to Maven
$ mvn package -Dscan.link.VCS=https://github.com/myorg/my-super-project/tree/my-new-feature
Add the following to gradle-enterprise.xml
<gradleEnterprise>
  <buildScan>
    <links>
      <link>
        <name>my link</name>
        <url>http://my-site.com</url>
      </link>
    </links>
  </buildScan>
</gradleEnterprise>
Add the following to a project pom.xml
<project>
  ...
  <pluginManagement>
    <plugins>
      <plugin>
        <groupId>com.gradle</groupId>
        <artifactId>gradle-enterprise-maven-extension</artifactId>
        <configuration>
          <gradleEnterprise>
            <buildScan>
              <links>
                <link>
                  <name>my link</name>
                  <url>http://my-site.com</url>
                </link>
              </links>
            </buildScan>
          </gradleEnterprise>
        </configuration>
      </plugin>
    </plugins>
  </pluginManagement>
</project>

Prefer the programmatic access. If specified in parent POM, links will be applied to all projects inheriting from it.

Links can also be added in your project POM.

The <name> is simply a string identifier that you choose and that means something to you.

You can see the effect of a custom link in figure 2, which shows how a label for a given VCS (here GitHub) becomes a hyperlink that anyone viewing the build scan can follow.

The Develocity Maven extension imposes limits on captured links:

  • maximum link count: 20

  • maximum link label length: 100 characters

  • maximum link url length: 100,000 characters for Develocity Maven extension 1.11+; 1,000 characters otherwise

Adding custom values

Some information just isn’t useful without context. What does "1G" mean? You might guess that it represents 1 gigabyte, but of what? It’s only when you attach the label "Max heap size for build" that it makes sense. The same applies to git commit IDs, for example, which could be interpreted as some other checksum without a suitable label.

Custom values are designed for these cases that require context. They’re standard key-value pairs, in which the key is a string label of your choosing and the values are also strings, often evaluated from the build environment.

buildScan.value("my name", "my value");
Add the scan.value.<name>=<value> system property to Maven
$ mvn package -Dscan.value.CIBuildType=QA_Build
Add the following to gradle-enterprise.xml
<gradleEnterprise>
  <buildScan>
    <values>
      <value>
        <name>my name</name>
        <value>my value</value>
      </value>
    </values>
  </buildScan>
</gradleEnterprise>
Add the following to a project pom.xml
<project>
  ...
  <pluginManagement>
    <plugins>
      <plugin>
        <groupId>com.gradle</groupId>
        <artifactId>gradle-enterprise-maven-extension</artifactId>
        <configuration>
          <gradleEnterprise>
            <buildScan>
              <values>
                <value>
                  <name>Build Number</name>
                  <value>${project.buildNumber}</value>
                </value>
              </values>
            </buildScan>
          </gradleEnterprise>
        </configuration>
      </plugin>
    </plugins>
  </pluginManagement>
</project>

Prefer the programmatic access. If specified in parent POM, custom values will be applied to all projects inheriting from it.

As with tags, you can filter build scans by custom values in Develocity.

The Develocity Maven extension imposes limits on captured custom values:

  • maximum custom value count: 1,000

  • maximum custom value key length: 1,000 characters

  • maximum custom value value length: 100,000 characters

Callbacks

The Build Scan API allows to programmatically interact with the build scan configuration of the Develocity Maven extension. Please see the Javadoc for the complete API documentation.

Executing operations at the end of the build

(Maven extension v1.2+)

What if you want to execute some code based on data that is only available late in the build? For example, you might want to label a build as "built-from-clean" if the clean goal was run. But you don’t know if that’s the case until the goal execution plan is ready.

The Maven extension provides a buildFinished() hook that you can use for these situations. It defers attaching custom data until the build has finished running. As an example, imagine you want to report how much disk space was taken up by the output directory. The build doesn’t know this until it’s finished, so the solution is to calculate the disk space and attach it to a custom value in the buildFinished() hook:

File outputDir = new File(mavenSession.getCurrentProject().getBuild().getOutputDirectory());
buildScan.buildFinished(buildResult -> {
    long size = org.apache.commons.io.FileUtils.sizeOfDirectory(outputDir);
    buildScan.value("Disk usage (target dir)", String.valueOf(size));
});
Adding data at the end of the build is not available via command-line argument.
Adding data at the end of the build is not available via XML configuration.

The buildFinished() action has access to a BuildResult instance that you can use to determine whether the build failed or not, like so:

buildScan.buildFinished(buildResult -> {
    buildResult.getFailures().forEach(failure ->
        buildScan.value("Failed with", failure.getMessage())
    );
});
Adding data at the end of the build is not available via command-line argument.
Adding data at the end of the build is not available via XML configuration.

Executing operations when a build scan is published

(Maven extension v1.2+)

You might want to perform a custom operation when a build scan is published, like notifying an internal tool of your company. To do this , you can use the BuildScanApi#buildScanPublished() method:

buildScan.buildScanPublished(it -> {
    try {
        Files.write(Paths.get("buildScans.txt"), it.getBuildScanId().getBytes(), StandardOpenOption.APPEND);
    } catch (IOException e) {
        throw new UncheckedIOException("Failed to write to journal", e);
    }
});
Executing operations when a build scan is published cannot be configured via command-line argument.
Executing operations when a build scan is published cannot be configured via XML.

Executing expensive operations

(Maven extension v1.2+)

Some data that you may wish to add to your build scan can be expensive to capture. For example, capturing the Git commit ID may require executing the git command as an external process, which is expensive. To do this without slowing your build down, you can use the BuildScanApi#background() method:

buildScan.background(api -> {
    try {
        File projectDir = mavenSession.getCurrentProject().getBasedir();
        String commitId = org.eclipse.jgit.lib.ObjectId.toString(
            org.eclipse.jgit.api.Git.open(projectDir)
                .getRepository()
                .resolve("HEAD")
        );
        api.value("Git Commit ID", commitId);
    } catch (IOException e) {
        throw new UncheckedIOException("Failed to read Git Commit ID", e);
    }
});
Doing expensive work in the background cannot be configured via command-line argument.
Doing expensive work in the background cannot be configured via XML.

This method takes a function that will be executed on a separate thread, which allows Maven to continue without waiting for the expensive work to complete.

All background work will be completed before finishing the build and publishing the build scan.

Any errors that are thrown by the background action will be logged and captured in the build scan.

See the BuildScanApi#background() API reference for more information.

Executing operations only once

(Maven extension v1.2.3+)

You may want to ensure that a given operation is only executed once for the whole execution of a multi-project Maven build.

The Maven extension provides an executeOnce() hook that you can use for these situations. It must be provided with an identifier, and can call any service provided by the API. The identifier is used to guarantee that the provided action will be executed at most once.

// This will be executed once
buildScan.executeOnce("capture custom data", api -> api.tag("my custom tag"));
// This will not be executed and will silently be ignored
buildScan.executeOnce("capture custom data", api -> api.tag("my other custom tag"));
// This will be executed once
buildScan.executeOnce("publish to journal", api -> api.buildScanPublished(journalServer::add));
Running custom build scan configuration logic once is not available via command-line argument.
Running custom build scan configuration logic once is not available via XML configuration.

Obfuscating identifying data

(Maven extension v1.3.1+)

Build scans capture certain identifying information such as the operating system username, hostname and network addresses. You may choose to obfuscate this data so that it is not decipherable in build scans when viewed. To do this, you can use the BuildScanApi#obfuscation() method.

With Maven extension v1.6.3+, you can register obfuscation values on the gradle-enterprise.xml. These will always be applied, even in case of very early build failures, that would prevent programmatic configuration via the BuildScan API. If the BuildScan API gets eventually called, obfuscation functions registered with it will have precedence over the values defined via XML.

The following examples show registering obfuscation functions for the different identifying data.

Obfuscating the username using the Programmatic configuration
buildScan.obfuscation(obfuscation -> obfuscation.username(s -> s.chars()
    .mapToObj(c -> String.valueOf(Character.getNumericValue(c)))
    .collect(java.util.stream.Collectors.joining())
));
Obfuscating the username cannot be configured via command-line argument.
Obfuscating the username via gradle-enterprise.xml (Maven extension v1.6.3+)
<gradleEnterprise>
  <buildScan>
    <obfuscation>
      <!-- Use a redacted value. -->
      <username>obfuscated</username>
    </obfuscation>
  </buildScan>
</gradleEnterprise>
---
<gradleEnterprise>
  <buildScan>
    <obfuscation>
      <!-- Use Spring Expression Language. The 'username' variable can be used to get access to the username that would be captured. -->
      <username>#{username.substring(0,1)}</username>
    </obfuscation>
  </buildScan>
</gradleEnterprise>
---
<gradleEnterprise>
  <buildScan>
    <obfuscation>
      <!-- Use Spring Expression Language. The 'sha512' method can be used. -->
      <username>#{sha512(username)}</username>
    </obfuscation>
  </buildScan>
</gradleEnterprise>
Obfuscating the hostnames using the Programmatic configuration
buildScan.obfuscation(obfuscation -> obfuscation.hostname(s -> s.chars()
    .mapToObj(c -> String.valueOf(Character.getNumericValue(c)))
    .collect(java.util.stream.Collectors.joining())
));
Obfuscating the hostnames cannot be configured via command-line argument.
Obfuscating the hostnames via gradle-enterprise.xml (Maven extension v1.6.3+)
<gradleEnterprise>
  <buildScan>
    <obfuscation>
      <!-- Use a redacted value. -->
      <hostname>obfuscated</hostname>
    </obfuscation>
  </buildScan>
</gradleEnterprise>
---
<gradleEnterprise>
  <buildScan>
    <obfuscation>
      <!-- Use Spring Expression Language. -->
      <hostname>#{isTrue(env['CI']) ? 'CI agent' : 'Local agent'}</hostname>
    </obfuscation>
  </buildScan>
</gradleEnterprise>
Obfuscating the IP addresses using the Programmatic configuration
buildScan.obfuscation(obfuscation -> obfuscation.ipAddresses(addresses -> addresses.stream()
    .map(address -> "0.0.0.0")
    .collect(java.util.stream.Collectors.toList())
));
Obfuscating the IP addresses cannot be configured via command-line argument.
Obfuscating the IP addresses via gradle-enterprise.xml (Maven extension v1.6.3+)
<gradleEnterprise>
  <buildScan>
    <obfuscation>
      <!-- Use a redacted value.-->
      <ipAddresses>#{{'0.0.0.0'}}</ipAddresses>
    </obfuscation>
  </buildScan>
</gradleEnterprise>
---
<gradleEnterprise>
  <buildScan>
    <obfuscation>
      <!-- Use Spring Expression Language. The 'sha512' method can be used. The 'ipAddresses' variable can be used to get access to the list of IP addresses that would be captured. -->
      <ipAddresses>#{sha512(ipAddresses)}</ipAddresses>
    </obfuscation>
  </buildScan>
</gradleEnterprise>

See the BuildScanApi#obfuscation() API reference for more information.

Troubleshooting

Failed background build scan uploads

When using background build scan uploading (default behaviour since Maven extension version 1.5, see this section for configuration options) upload failures are not visible in the build logging due to occurring in a background process after the build has finished. Instead, errors are logged to a file located at ~/.m2/.gradle-enterprise/build-scan-data/upload-failure.log. If this additional information does not help to resolve the failure, please contact technical support and include the contents of this log file.

If the background upload process fails to start, a warning is shown in the build console and uploading is performed in the build process. If this occurs, please contact technical support with the log files located at ~/.m2/.gradle-enterprise/build-scan-data/<<extension-version>>/pending-uploads/*.log.

Slow resolution of host name

Build scans attempt to determine the host name of the machine. An issue affecting macOS can cause a delay when doing this in some environments.

If you see a warning during your build that resolving the local host name is slow, you can workaround the problem by adding a host name mapping to your /etc/hosts file.

Add these lines to your /etc/hosts file, substituting your computer name for 'mbpro' in the below snippet:

/etc/hosts
127.0.0.1   localhost mbpro.local
::1         localhost mbpro.local

Forked Maven builds

Several Maven plugins fork a new Maven build during the execution of a build. When the project is configured to publish a Build Scan, the forked Maven build will publish one as well. Depending on the use case, this behavior is desirable or not. The Develocity Maven extension does not detect if it’s executed within a forked Maven build to avoid publishing a Build Scan. In some circumstances and specific setups it can lead to errors on the forked Maven build and we then advise you to disable the Build Scan functionality of the Develocity Maven extension for such builds. This does not affect the use of the Build Cache.

The following sections show how to disable publishing a Build Scan for various Maven plugins that spawn forked Maven builds.

Maven invoker plugin

For the Maven invoker plugin set the gradle.scan.disabled system property to true.

pom.xml
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-invoker-plugin</artifactId>
    <configuration>
        ...
        <properties>
            <gradle.scan.disabled>true</gradle.scan.disabled>
        </properties>
        ...
    </configuration>
    ...
</plugin>
Maven verifier

For the Maven verifier you can set the gradle.scan.disabled CLI option on the Verifier to true.

verifier.addCliOption("-Dgradle.scan.disabled=true");
Maven archetype plugin

While integration testing an archetype with the Maven archetype plugin a Maven build will be forked. To disable Build Scan publishing, you can set the gradle.scan.disabled system property to true.

pom.xml
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-archetype-plugin</artifactId>
    <configuration>
        ...
        <properties>
            <gradle.scan.disabled>true</gradle.scan.disabled>
        </properties>
        ...
    </configuration>
    ...
</plugin>
Maven release plugin

For the Maven release plugin set the gradle.scan.disabled system property to true.

pom.xml
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-release-plugin</artifactId>
    <configuration>
        ...
        <arguments>
            -Dgradle.scan.disabled=true
        </arguments>
        ...
    </configuration>
    ...
</plugin>

Using the Build Cache

The Build Cache speeds up your builds by reusing outputs from any previous build, on any machine that is connected to the same Build Cache backend. It does this by reducing the inputs of a goal execution down to a strong hash key and storing the execution’s output under that key. It supports a local Build Cache that allows other subsequent builds on the same machine to reuse the outputs whenever they execute a goal with the same inputs. The full benefit of the Build Cache is realized when also using the remote backend that Develocity provides. This remote Build Cache allows you to share cached outputs across your whole team, including local and CI builds.

Please refer to the Build Cache guide for step-by-step instructions on how to get started and in-depth explanations of important concepts. Moreover, the guide shows how to measure the effectiveness of the Build Cache in your project and explains how to roll out the Build Cache in your organization.

The build caching functionality for Maven requires a Develocity license. The free scans.gradle.com server does not allow using the Build Cache.

Configuring the Build Cache

In order to use build caching for Apache Maven, you need to configure the location of your Develocity server.

gradleEnterprise.setServer("https://gradle-enterprise.mycompany.com");
$ mvn package -Dgradle.enterprise.url=https://develocity.mycompany.com
Add the following to gradle-enterprise.xml
<gradleEnterprise>
  <server>
    <url>https://gradle-enterprise.mycompany.com</url>
  </server>
</gradleEnterprise>

The precise URL you need depends on the hostname that your Develocity instance has been configured with. If in doubt, be sure to ask whomever manages that instance.

You may encounter a warning about an untrusted certificate when connecting to Develocity over HTTPS. The ideal solution is for someone to add a valid SSL certificate to the Develocity instance, but we recognise that you may not be able to do that. In this case, set the allowUntrustedServer option to true:

gradleEnterprise.setAllowUntrustedServer(true);
$ mvn package -Dgradle.enterprise.allowUntrustedServer=true
Add the following to gradle-enterprise.xml
<gradleEnterprise>
  <server>
    <allowUntrusted>true</allowUntrusted>
  </server>
</gradleEnterprise>
This is a convenient workaround during the initial evaluation, but it is a serious security issue and should not be used in production.

Configuring the local Build Cache

The extension uses a local Build Cache to store build outputs in the local filesystem. It prevents network round-trips by storing both outputs that local builds created, as well as outputs that were downloaded from the remote Build Cache.

Disabling the local Build Cache

The local Build Cache is enabled by default. This can be changed by setting the enabled option to false.

Using the Programmatic configuration (Maven extension v1.7+)
buildCache.getLocal().setEnabled(false);
$ mvn package -Dgradle.cache.local.enabled=false
Add the following to gradle-enterprise.xml
<gradleEnterprise>
  <buildCache>
    <local>
      <enabled>false</enabled>
    </local>
  </buildCache>
</gradleEnterprise>
Disabling local store

(Maven extension 1.14+)

By default, outputs are stored in the local Build Cache if it is enabled and the build includes the clean lifecycle phase. Storing outputs in the local Build Cache can be disabled explicitly by setting the storeEnabled option to false.

Using the Programmatic configuration (Maven extension v1.7+)
buildCache.getLocal().setStoreEnabled(false);
$ mvn package -Dgradle.cache.local.storeEnabled=false
Add the following to gradle-enterprise.xml
<gradleEnterprise>
  <buildCache>
    <local>
      <storeEnabled>false</storeEnabled>
    </local>
  </buildCache>
</gradleEnterprise>
Changing the local Build Cache directory

The local Build Cache is located at ${user.home}/.m2/.gradle-enterprise/build-cache by default. This can be changed by setting the directory option.

Using the Programmatic configuration (Maven extension v1.7+)
buildCache.getLocal().setDirectory(new File("path/to/local/build-cache"));
$ mvn package -Dgradle.cache.local.directory=path/to/local/build-cache
Add the following to gradle-enterprise.xml
<gradleEnterprise>
  <buildCache>
    <local>
      <directory>/path/to/local/build-cache</directory>
    </local>
  </buildCache>
</gradleEnterprise>

It is a common practice in large organizations to put the user home on a network share. Since the underlying motivation of a local Build Cache is to prevent network round-trips, you should explicitly configure the local Build Cache directory to a path on the local filesystem.

Configuring local Build Cache cleanup

To prevent the local Build Cache from growing in size indefinitely, the local Build Cache directory is cleaned up periodically. By default, the cleanup interval is 24 hours and the retention time is 7 days. The cleanup can be disabled by setting the enabled option to false.

Using the Programmatic configuration (Maven extension v1.7+)
buildCache.getLocal().getCleanupPolicy().setEnabled(false);
$ mvn package -Dgradle.cache.local.cleanup.enabled=false
Add the following to gradle-enterprise.xml
<gradleEnterprise>
  <buildCache>
    <local>
      <cleanup>
        <enabled>false</enabled>
      </cleanup>
    </local>
  </buildCache>
</gradleEnterprise>

The cleanup interval and retention time are controlled by the interval and retention options. The formats accepted are based on the ISO-8601 duration format PnDTnHnMn.nS.

Using the Programmatic configuration (Maven extension v1.7+)
buildCache.getLocal().getCleanupPolicy().setRetentionPeriod(java.time.Duration.ofDays(30));
buildCache.getLocal().getCleanupPolicy().setCleanupInterval(java.time.Duration.ofDays(10));
$ mvn package -Dgradle.cache.local.cleanup.retention=P30D -Dgradle.cache.local.cleanup.interval=P10D
Add the following to gradle-enterprise.xml
<gradleEnterprise>
  <buildCache>
    <local>
      <cleanup>
        <retention>P30D</retention>
        <interval>P10D</interval>
      </cleanup>
    </local>
  </buildCache>
</gradleEnterprise>
Using the Build Cache to store fingerprints of external dependencies

The Build Cache can optionally be used to store and retrieve fingerprints of external dependency jar files, in addition to the local fingerprint cache in the user’s Maven home directory,

When enabled, fingerprint recalculation across machines is avoided. This offers a considerable performance improvement when the build has large jar file dependencies or when the build is executed on machines with slow disk I/O.

However, in case of high latency to the remote Build Cache, it can have an adverse effect on build performance.

Therefore, storing and retrieving external dependency jar fingerprints in the Build Cache is disabled by default since version 1.13 of the Develocity Maven extension. It must be enabled explicitly via a system property.

Toggling caching of fingerprints in the Build Cache is not available programmatically.
$ mvn package -Dgradle.enterprise.cacheFingerprintsInBuildCache=true
Toggling caching of fingerprints in the Build Cache is not available via XML configuration.

With a remote Build Cache, it is possible that the round-trip time to store and retrieve fingerprints exceeds the time to calculate fingerprints. Benchmarking your build with and without fingerprint caching is advised.

Working offline

In order to work offline, the extension needs to have run in online mode at least once in the past 24 hours to check whether the given Develocity server allows build caching for Maven. The result of this check is stored in a token in the user home. As long as you are working online, the token is refreshed every hour. The local Build Cache will keep working in offline mode until that token expires after 24 hours.

Configuring the remote Build Cache

Develocity provides a Build Cache node that is built into the server. Additionally, remote Build Cache nodes can be spun up and connected to the server. By default, the built-in Build Cache node of the Develocity server is used.

Using a different Build Cache node

The address of the remote Build Cache node can be configured in the server option.

Using the Programmatic configuration (Maven extension v1.7+)
buildCache.getRemote().getServer().setUrl(java.net.URI.create("http://my-node/cache/"));
$ mvn package -Dgradle.cache.remote.url=http://my-node/cache/
Add the following to gradle-enterprise.xml
<gradleEnterprise>
  <buildCache>
    <remote>
      <server>
        <url>http://my-node/cache/</url>
      </server>
    </remote>
  </buildCache>
</gradleEnterprise>

Note that you still need to configure the address of your Develocity server in the top-level server option.

Similar to the top-level Develocity server configuration, the remote Build Cache server configuration also provides an allowUntrusted option to circumvent certificate warnings:

Using the Programmatic configuration (Maven extension v1.7+)
buildCache.getRemote().getServer().setAllowUntrusted(true);
$ mvn package -Dgradle.cache.remote.allowUntrustedServer=true
Add the following to gradle-enterprise.xml
<gradleEnterprise>
  <buildCache>
    <remote>
      <server>
        <url>http://my-node/cache/</url>
        <allowUntrusted>true</allowUntrusted>
      </server>
    </remote>
  </buildCache>
</gradleEnterprise>
This is a convenient workaround during the initial evaluation, but it is a serious security issue and should not be used in production.
Supplying remote Build Cache credentials

When using Maven extension version 1.15+, Develocity 2022.3+ and Develocity Build Cache Nodes 13+, the same access key credential used for Build Scan publishing, Test Distribution and other functions can be used for build cache access control.

Alternatively, a specific username and password can be specified that will be used instead of any available access key. The username and password can be specified directly in your Develocity configuration, or via a Maven settings.xml file.

Using the Programmatic configuration (Maven extension v1.7+)
buildCache.getRemote().getServer().getCredentials().setUsername("my-username");
buildCache.getRemote().getServer().getCredentials().setPassword("my-password");
$ mvn package -Dgradle.cache.remote.username=my-username -Dgradle.cache.remote.password=my-password
Add the following to gradle-enterprise.xml
<gradleEnterprise>
  <buildCache>
    <remote>
      <server>
        <credentials>
          <username>my-username</username>
          <password>my-password</password>
        </credentials>
      </server>
    </remote>
  </buildCache>
</gradleEnterprise>

Instead of putting plain-text passwords into the configuration file, you should inject them via environment variables as demonstrated below.

gradle-enterprise.xml
<gradleEnterprise>
  <buildCache>
    <remote>
      <server>
        <credentials>
          <username>${env.GRADLE_ENTERPRISE_CACHE_USERNAME}</username>
          <password>${env.GRADLE_ENTERPRISE_CACHE_PASSWORD}</password>
        </credentials>
      </server>
    </remote>
  </buildCache>
</gradleEnterprise>
Supplying remote Build Cache credentials via Maven settings.xml

Alternatively, you can configure the Build Cache node credentials in the settings.xml file, using Maven’s password encryption feature to safely store these credentials.

Note that credentials specified directly via Develocity configuration take precedence over the credentials specified in a settings.xml file.

<user-home>/.m2/settings.xml
<servers>
  <server>
    <id>my-node</id>
    <username>my-username</username>
    <password>my-password</password>
  </server>
</servers>

The Build Cache node with the ID my-node can then be referenced in the remote Build Cache configuration.

Using the Programmatic configuration (Maven extension v1.7+)
buildCache.getRemote().getServer().setServerId("my-node");
$ mvn package -Dgradle.cache.remote.serverId=my-node
Add the following to gradle-enterprise.xml
<gradleEnterprise>
  <buildCache>
    <remote>
      <server>
        <id>my-node</id>
        <url>http://my-node/cache/</url>
      </server>
    </remote>
  </buildCache>
</gradleEnterprise>
Disabling the remote Build Cache

The remote Build Cache is enabled by default. This can be changed by setting the enabled option to false.

Using the Programmatic configuration (Maven extension v1.7+)
buildCache.getRemote().setEnabled(false);
$ mvn package -Dgradle.cache.remote.enabled=false
Add the following to gradle-enterprise.xml
<gradleEnterprise>
  <buildCache>
    <remote>
      <enabled>false</enabled>
    </remote>
  </buildCache>
</gradleEnterprise>
Enabling remote store

Since the remote Build Cache is shared with other developers and CI machines, storing in the remote Build Cache is disabled by default. Storing outputs in the remote Build Cache can be enabled by setting the storeEnabled option to true.

Using the Programmatic configuration (Maven extension v1.7+)
buildCache.getRemote().setStoreEnabled(true);
$ mvn package -Dgradle.cache.remote.storeEnabled=true
Add the following to gradle-enterprise.xml
<gradleEnterprise>
  <buildCache>
    <remote>
      <storeEnabled>true</storeEnabled>
    </remote>
  </buildCache>
</gradleEnterprise>

In general, the remote Build Cache should only be populated by controlled build environments such as CI servers. Therefore, the recommendation is to only enable it on the CI server.

Using Expect-Continue

(Maven extension 1.12+)

The HTTP Build Cache client allows opt-in use of HTTP Expect-Continue. This causes PUT requests to happen in two parts: first a check whether a body would be accepted, then transmission of the body if the server indicates it will accept it. This is particularly suitable for Build Cache servers that routinely redirect or reject PUT requests, as it avoids transmitting the cache entry just to have it rejected (e.g. the cache entry is larger than the Build Cache will allow). This additional check incurs extra latency when the server accepts the request, but reduces latency when the request is rejected or redirected.

While the Develocity Build Cache Node supports Expect-Continue, not all HTTP servers and proxies reliably do. Be sure to check that your Build Cache server does support it before enabling.

buildCache.getRemote().getServer().setUseExpectContinue(true);
$ mvn package -Dgradle.cache.remote.useExpectContinue=true
Add the following to gradle-enterprise.xml
<gradleEnterprise>
  <buildCache>
    <remote>
      <server>
        <useExpectContinue>true</useExpectContinue>
      </server>
    </remote>
  </buildCache>
</gradleEnterprise>
Redirects

(Maven extension 1.13+)

3xx redirecting responses will be followed automatically.

Servers must take care when redirecting PUT requests as only 307 and 308 redirect responses will be followed with a PUT request. All other redirect responses will be followed with a GET request, as per RFC 7231, without the entry payload as the body.

Allowing insecure protocols

(Maven extension 1.13+)

Using the remote Build Cache by default enforces the use of HTTPS to make sure your data is only sent via encrypted connections. If the Build Cache server, or any server in a redirect chain, does not use HTTPS the request will be aborted. This validation can be disabled by setting the allowInsecureProtocol option to true.

buildCache.getRemote().getServer().setAllowInsecureProtocol(true);
$ mvn package -Dgradle.cache.remote.allowInsecureProtocol=true
Add the following to gradle-enterprise.xml
<gradleEnterprise>
  <buildCache>
    <remote>
      <server>
        <allowInsecureProtocol>true</allowInsecureProtocol>
      </server>
    </remote>
  </buildCache>
</gradleEnterprise>
This is a convenient workaround during the initial evaluation, but it is a serious security issue and should not be used in production.

Runtime classpath normalization

A common pattern is to have some build logic that writes volatile data to some files. For example your build might write a timestamp to a build.properties file. This helps to identify the source of a build artifact. However, this also causes problems with build caching: when Maven executes tests, the runtime classpath becomes part of the cache key for that test run. Any resource file that is processed by Maven is also added to that runtime classpath. In consequence, if a build generates a build timestamp, this causes the runtime classpath to change on every build invocation, resulting in cache misses. To circumvent this situation the Maven extension provides several configuration options to normalize the runtime classpath in order to deal with this volatility.

Ignoring arbitrary files

The following snippet shows you how to ignore any file called META-INF/build.properties on any runtime classpath in the given project. You can share this setting across many projects by putting it in the pluginManagement section of your parent POM. You can use ANT-style patterns like META-INF/**/*.sql as well.

Using the Programmatic configuration (Maven extension v1.15+)
buildCache.registerNormalizationProvider(context -> context
    .configureRuntimeClasspathNormalization(
        normalization -> normalization
            .setIgnoredFiles("META-INF/build.properties")
    ));
<pluginManagement>
  <plugins>
    <plugin>
      <groupId>com.gradle</groupId>
      <artifactId>gradle-enterprise-maven-extension</artifactId>
      <configuration>
        <gradleEnterprise>
          <normalization>
            <runtimeClassPath>
              <ignoredFiles>
                <ignoredFile>META-INF/build.properties</ignoredFile>
              </ignoredFiles>
            </runtimeClassPath>
          </normalization>
        </gradleEnterprise>
      </configuration>
    </plugin>
  </plugins>
</pluginManagement>

Files matching the patterns META-INF/maven/**/pom.xml and META-INF/maven/**/pom.properties are always ignored.

Ignoring specific entries in properties files

(Maven extension 1.8+)

Since properties files are a common file format to store data generated by the build, the normalization DSL provides special support for ignoring specific entries in properties files. Again, ANT-style patterns can be used to match relevant properties files. In the following example any files named build.properties in com/example or any subdirectory are matched and the value of the property build.timestamp is ignored:

Using the Programmatic configuration (Maven extension v1.15+)
buildCache.registerNormalizationProvider(context -> context
    .configureRuntimeClasspathNormalization(
        normalization -> normalization
            .addPropertiesNormalization("com/example/**/build.properties", "build.timestamp")
    ));
<pluginManagement>
  <plugins>
    <plugin>
      <groupId>com.gradle</groupId>
      <artifactId>gradle-enterprise-maven-extension</artifactId>
      <configuration>
        <gradleEnterprise>
          <normalization>
            <runtimeClassPath>
              <propertiesNormalizations>
                <propertiesNormalization>
                  <path>com/example/**/build.properties</path>
                  <ignoredProperties>
                    <ignore>build.timestamp</ignore>
                  </ignoredProperties>
                </propertiesNormalization>
              </propertiesNormalizations>
            </runtimeClassPath>
          </normalization>
        </gradleEnterprise>
      </configuration>
    </plugin>
  </plugins>
</pluginManagement>

A common location to store properties files is the META-INF directory. Thus, the normalization DSL provides a shortcut for normalizing files matching META-INF/**/*.properties

Using the Programmatic configuration (Maven extension v1.15+)
buildCache.registerNormalizationProvider(context -> context
    .configureRuntimeClasspathNormalization(
        normalization -> normalization
            .configureMetaInf(metaInf -> metaInf.setIgnoredProperties("app.version"))
    ));
<pluginManagement>
  <plugins>
    <plugin>
      <groupId>com.gradle</groupId>
      <artifactId>gradle-enterprise-maven-extension</artifactId>
      <configuration>
        <gradleEnterprise>
          <normalization>
            <runtimeClassPath>
              <metaInf>
                <ignoredProperties>
                  <ignore>app.version</ignore>
                </ignoredProperties>
              </metaInf>
            </runtimeClassPath>
          </normalization>
        </gradleEnterprise>
      </configuration>
    </plugin>
  </plugins>
</pluginManagement>

Normalizing contents of META-INF

(Maven extension 1.8+)

The <metaInf> configuration element offers even more convenience configuration settings for normalizing the contents of the META-INF directory. For example, you may only want to ignore one or more attributes in MANIFEST files, e.g. Implementation-Version instead of ignoring the whole file. This can be done as follows:

Using the Programmatic configuration (Maven extension v1.15+)
buildCache.registerNormalizationProvider(context -> context
    .configureRuntimeClasspathNormalization(
        normalization -> normalization
            .configureMetaInf(metaInf -> metaInf.setIgnoredAttributes("Implementation-Version"))
    ));
<pluginManagement>
  <plugins>
    <plugin>
      <groupId>com.gradle</groupId>
      <artifactId>gradle-enterprise-maven-extension</artifactId>
      <configuration>
        <gradleEnterprise>
          <normalization>
            <runtimeClassPath>
              <metaInf>
                <ignoredAttributes>
                  <ignore>Implementation-Version</ignore>
                </ignoredAttributes>
              </metaInf>
            </runtimeClassPath>
          </normalization>
        </gradleEnterprise>
      </configuration>
    </plugin>
  </plugins>
</pluginManagement>

If you want to ignore MANIFEST files completely there’s the <ignoreManifest> configuration as a shorthand for that. It’s the equivalent of adding META-INF/MANIFEST.MF as an ignored file.

Using the Programmatic configuration (Maven extension v1.15+)
buildCache.registerNormalizationProvider(context -> context
    .configureRuntimeClasspathNormalization(
        normalization -> normalization
            .configureMetaInf(metaInf -> metaInf.setIgnoreManifest(true))
    ));
<pluginManagement>
  <plugins>
    <plugin>
      <groupId>com.gradle</groupId>
      <artifactId>gradle-enterprise-maven-extension</artifactId>
      <configuration>
        <gradleEnterprise>
          <normalization>
            <runtimeClassPath>
              <metaInf>
                <ignoreManifest>true</ignoreManifest>
              </metaInf>
            </runtimeClassPath>
          </normalization>
        </gradleEnterprise>
      </configuration>
    </plugin>
  </plugins>
</pluginManagement>

In situations where you have several changing files in the META-INF directory, you might want to ignore the contents of that directory completely. The <ignoreCompletely> configuration is a shorthand for adding META-INF/** to ignored files.

Using the Programmatic configuration (Maven extension v1.15+)
buildCache.registerNormalizationProvider(context -> context
    .configureRuntimeClasspathNormalization(
        normalization -> normalization
            .configureMetaInf(metaInf -> metaInf.setIgnoreCompletely(true))
    ));
<pluginManagement>
  <plugins>
    <plugin>
      <groupId>com.gradle</groupId>
      <artifactId>gradle-enterprise-maven-extension</artifactId>
      <configuration>
        <gradleEnterprise>
          <normalization>
            <runtimeClassPath>
              <metaInf>
                <ignoreCompletely>true</ignoreCompletely>
              </metaInf>
            </runtimeClassPath>
          </normalization>
        </gradleEnterprise>
      </configuration>
    </plugin>
  </plugins>
</pluginManagement>

The more you ignore using runtime classpath normalization, the more likely false cache hits become. You should use these features with care and try to narrow down the scope of normalizations as much as possible, e.g. you should prefer normalizing a single MANIFEST attribute over ignoring the META-INF directory completely.

System property normalization

It is common to use system properties as vehicles to transport information between different executions. It is also not unheard of that these system properties do not have a direct effect on the results of the execution of specific goals.

One example would be having a temporary folder name or a timestamp passed to a test goal. These will change in each execution, but in certain cases, do not determine the result of these executions. These are the cases where system property normalization can be used.

Ignoring system properties by keys

The normalization provides a way to ignore certain system properties by their key

Using the Programmatic configuration (Maven extension v1.18+)
buildCache.registerNormalizationProvider(context -> context
    .configureSystemPropertiesNormalization(
        normalization -> normalization
            .setIgnoredKeys("examplePropertyName")
    ));
<pluginManagement>
  <plugins>
    <plugin>
      <groupId>com.gradle</groupId>
      <artifactId>gradle-enterprise-maven-extension</artifactId>
      <configuration>
        <gradleEnterprise>
          <normalization>
            <systemProperties>
              <ignoredKeys>
                <ignore>examplePropertyName</ignore>
              </ignoredKeys>
            </systemProperties>
          </normalization>
        </gradleEnterprise>
      </configuration>
    </plugin>
  </plugins>
</pluginManagement>

Declaring inputs and outputs

The Build Cache works based on inputs and outputs. For each supported goal execution a cache key is calculated by inspecting all inputs. The cache key is then used to lookup the outputs of that execution in the cache. If no result can be found, the goal is executed and the outputs are stored in the Build Cache under the cache key. This section explains how input and outputs can be fine-tuned.

The extension already configures caching for some plugins and goals out of the box. A list of those plugins and goals can be seen in Cacheable plugins and goals.

Adding additional inputs and outputs to a plugin or execution

The predefined inputs and outputs of any supported goal can be augmented by declaring them in the <pluginManagement> section of your pom.xml file. A common use case for declaring additional input files are test cases that read from a location that is not automatically tracked. For example, you might have Cucumber specification files located in the src/test/specs directory. Any change to the files in that directory may change the result of running the tests. So changing specification files should result in rerunning the tests and not loading the results from the cache. Without additional configuration the Build Cache is unaware of these additional inputs and will therefore load the result from the Build Cache even if specification files change.

Declaring additional inputs

The following will add the directory src/test/specs as an input to all executions of the Apache Maven Surefire plugin. Any files in that folder which match the given includes and excludes will then be tracked as part of the cache key:

Using the Programmatic configuration (Maven extension v1.15+)
buildCache.registerMojoMetadataProvider(context -> {
    context.withPlugin("maven-surefire-plugin",
        () -> context.inputs(inputs -> inputs
            .fileSet(
                "specs",
                "src/test/specs",
                fileSet -> fileSet
                    .include("**/*.feature")
                    .exclude("archive/**/*.feature")
                    .normalizationStrategy(MojoMetadataProvider.Context.FileSet.NormalizationStrategy.RELATIVE_PATH)
            ))
    );
});
<pluginManagement>
  <plugins>
    <plugin>
      <groupId>com.gradle</groupId>
      <artifactId>gradle-enterprise-maven-extension</artifactId>
      <configuration>
        <gradleEnterprise>
          <plugins>
            <plugin>
              <artifactId>maven-surefire-plugin</artifactId>
              <inputs>
                <fileSets>
                  <fileSet>
                    <name>specs</name>
                    <paths>
                      <path>src/test/specs</path>
                    </paths>
                    <includes>
                      <include>**/*.feature</include>
                    </includes>
                    <excludes>
                      <exclude>archive/**/*.feature</exclude>
                    </excludes>
                    <normalization>RELATIVE_PATH</normalization>
                  </fileSet>
                </fileSets>
              </inputs>
            </plugin>
          </plugins>
        </gradleEnterprise>
      </configuration>
    </plugin>
  </plugins>
</pluginManagement>

While processing inputs, various normalization strategies can be applied in order to raise the effectiveness of the Build Cache. In other words, normalization strategies are a way of ignoring changes to input files that are irrelevant for the goal execution. The following input normalization strategies are supported:

Normalization Strategy Description ignoreEmptyDirectories ignoreLineEndings

IGNORED_PATH

Considers the full content of files, but ignores their path.

Not Supported

Supported

NAME_ONLY

Considers the full content of files, but only tracks their name and not the rest of their path.

Supported

Supported

RELATIVE_PATH

The default strategy. Considers the full content of a file, but only tracks their path relative to their root directory. The root directory is the directory that was added as an input. The path of that root directory itself is ignored.

Supported

Supported

ABSOLUTE_PATH

Considers the full content of files as well as their absolute path. Using this strategy is strongly discouraged, as the project directory (and thus all absolute paths) are usually different on different machines, which prevents cache hits.

Supported

Supported

CLASSPATH

Considers only the information relevant for running Java code.

Not Supported

Supported

COMPILE_CLASSPATH

Considers only the information relevant for compiling Java code. This means for example that only class files are considered and private implementation details like method bodies are ignored.

Not Supported

Not Supported

Ignoring empty directories

(Maven extension 1.8+)

The NAME_ONLY, RELATIVE_PATH, and ABSOLUTE_PATH strategies support additional normalization options. Their sensitivity to the presence of empty directories in the source tree can be controlled. The default is to take empty directories into account. This means that adding an empty directory to the source tree will result in a cache miss. The following configuration causes empty directories to be ignored:

Using the Programmatic configuration (Maven extension v1.15+)
buildCache.registerMojoMetadataProvider(context -> {
    context.withPlugin("maven-surefire-plugin",
        () -> context.inputs(inputs -> inputs
            .fileSet(
                "specs",
                "src/test/specs",
                fileSet -> fileSet
                    .normalizationStrategy(MojoMetadataProvider.Context.FileSet.NormalizationStrategy.RELATIVE_PATH)
                    .emptyDirectoryHandling(MojoMetadataProvider.Context.FileSet.EmptyDirectoryHandling.IGNORE) (1)
            ))
    );
});
<pluginManagement>
  <plugins>
    <plugin>
      <groupId>com.gradle</groupId>
      <artifactId>gradle-enterprise-maven-extension</artifactId>
      <configuration>
        <gradleEnterprise>
          <plugins>
            <plugin>
              <artifactId>maven-surefire-plugin</artifactId>
              <inputs>
                <fileSets>
                  <fileSet>
                    <name>specs</name>
                    <paths>
                      <path>src/test/specs</path>
                    </paths>
                    <normalization>
                      <strategy>RELATIVE_PATH</strategy>
                      <ignoreEmptyDirectories>true</ignoreEmptyDirectories> (1)
                    </normalization>
                  </fileSet>
                </fileSets>
              </inputs>
            </plugin>
          </plugins>
        </gradleEnterprise>
      </configuration>
    </plugin>
  </plugins>
</pluginManagement>
1 Mark empty directories as ignorable

A common reason for having empty directories in the source tree is using a version control system like Git that only keeps tracks of files. When one developer deletes a directory tree on their machine and another developer pulls that change from the repository, Git will only delete the files contained in that directory tree leaving parent directories empty.

Ignoring line endings

(Maven extension 1.11+)

The ignoreLineEndings option allows authors to specify that line endings in text files should be normalized for Build Cache checks, so that files that only differ by line endings will be considered identical. Binary files, on the other hand, will not be affected by this normalization.

Line ending normalization only applies to text files encoded with the ASCII character set or one of its supersets (e.g., UTF-8). Text files encoded in a non-ASCII character set (e.g., UTF-16) will be treated as binary files and will not be subject to line ending normalization.

Using the Programmatic configuration (Maven extension v1.15+)
buildCache.registerMojoMetadataProvider(context -> {
    context.withPlugin("maven-surefire-plugin",
        () -> context.inputs(inputs -> inputs
            .fileSet(
                "specs",
                "src/test/specs",
                fileSet -> fileSet
                    .normalizationStrategy(MojoMetadataProvider.Context.FileSet.NormalizationStrategy.RELATIVE_PATH)
                    .lineEndingHandling(MojoMetadataProvider.Context.FileSet.LineEndingHandling.NORMALIZE) (1)
            ))
    );
});
<pluginManagement>
  <plugins>
    <plugin>
      <groupId>com.gradle</groupId>
      <artifactId>gradle-enterprise-maven-extension</artifactId>
      <configuration>
        <gradleEnterprise>
          <plugins>
            <plugin>
              <artifactId>maven-surefire-plugin</artifactId>
              <inputs>
                <fileSets>
                  <fileSet>
                    <name>specs</name>
                    <paths>
                      <path>src/test/specs</path>
                    </paths>
                    <normalization>
                      <strategy>RELATIVE_PATH</strategy>
                      <ignoreLineEndings>true</ignoreLineEndings> (1)
                    </normalization>
                  </fileSet>
                </fileSets>
              </inputs>
            </plugin>
          </plugins>
        </gradleEnterprise>
      </configuration>
    </plugin>
  </plugins>
</pluginManagement>
1 Mark line endings as ignorable

All strategies except COMPILE_CLASSPATH support this option.

The Maven extension normalizes line endings in source files when computing the Build Cache key for compile or testCompile goals of the maven-compiler-plugin.

Declaring additional outputs

Cucumber can be configured to generate various types of reports. These reports may be located in an output folder different from the default test report folder. In order to store them in the Build Cache for later retrieval the output location needs to be declared as an additional output. The following will add the additional output directory ${project.build.directory}/cucumber to the default-test execution of the surefire plugin. The contents of this directory will become part of the Build Cache archive for this execution.

Using the Programmatic configuration (Maven extension v1.15+)
buildCache.registerMojoMetadataProvider(context -> {
    context.withPlugin("maven-surefire-plugin", () -> {
            if ("cucumber-tests".equals(context.getMojoExecution().getExecutionId())) {
                context.outputs(outputs -> outputs.directory("cucumber-reports", "${project.build.directory}/cucumber"));
            }
        }
    );
});
<pluginManagement>
  <plugins>
    <plugin>
      <groupId>com.gradle</groupId>
      <artifactId>gradle-enterprise-maven-extension</artifactId>
      <configuration>
        <gradleEnterprise>
          <plugins>
            <plugin>
              <artifactId>maven-surefire-plugin</artifactId>
              <executions>
                <execution>
                  <id>cucumber-tests</id>
                  <outputs>
                    <directories>
                      <directory>
                        <name>cucumber-reports</name>
                        <path>${project.build.directory}/cucumber</path>
                      </directory>
                    </directories>
                  </outputs>
                </execution>
              </executions>
            </plugin>
          </plugins>
        </gradleEnterprise>
      </configuration>
    </plugin>
  </plugins>
</pluginManagement>

Configuring caching for a specific goal execution is not limited to declaring additional outputs. The same constructs for defining additional inputs that have been shown before can also be used for specific goal executions.

Overriding inputs and outputs

The predefined inputs and outputs of any supported goal that are used by the Develocity Maven extension can be overridden, i.e. redefined with a custom value. A common use case is to override the value of an input property because it contains an absolute path that would prevent cache hits on other machines. For example, the maven-checkstyle-plugin has a propertyExpansion input property that may contain an absolute path in some use cases.

<plugin>
  <artifactId>maven-checkstyle-plugin</artifactId>
  <configuration>
    <propertyExpansion>checkstyle.additional.suppressions.file=${project.basedir}/custom-suppressions.xml</propertyExpansion>
  </configuration>
</plugin>

In this case, the propertyExpansion input property can be redefined for the purpose of cache key computation in Develocity while the Maven goal’s implementation will continue to read the existing configuration.

Using the Programmatic configuration (Maven extension v1.15+)
buildCache.registerMojoMetadataProvider(context -> {
    context.withPlugin("maven-checkstyle-plugin",
        () -> context.inputs(inputs -> inputs
            .property("propertyExpansion", "checkstyle.additional.suppressions.file=ignored") (1)
            .fileSet(
                "checkstyle.additional.suppressions.file",
                "${project.basedir}/custom-suppressions.xml", (2)
                fileSet -> fileSet
                    .normalizationStrategy(MojoMetadataProvider.Context.FileSet.NormalizationStrategy.IGNORED_PATH)
                    .lineEndingHandling(MojoMetadataProvider.Context.FileSet.LineEndingHandling.NORMALIZE)
            )
        )
    );
});
<pluginManagement>
  <plugins>
    <plugin>
      <groupId>com.gradle</groupId>
      <artifactId>gradle-enterprise-maven-extension</artifactId>
      <configuration>
        <gradleEnterprise>
          <plugins>
            <plugin>
              <artifactId>maven-checkstyle-plugin</artifactId>
              <inputs>
                <properties>
                  <property>
                    <name>propertyExpansion</name>
                    <value>checkstyle.additional.suppressions.file=ignored</value> (1)
                  </property>
                </properties>
                <fileSets>
                  <fileSet>
                    <name>checkstyle.additional.suppressions.file</name>
                    <paths>
                      <path>${project.basedir}/custom-suppressions.xml</path> (2)
                    </paths>
                    <normalization>
                      <strategy>IGNORED_PATH</strategy>
                      <ignoreLineEndings>true</ignoreLineEndings>
                    </normalization>
                  </fileSet>
                </fileSets>
              </inputs>
            </plugin>
          </plugins>
        </gradleEnterprise>
      </configuration>
    </plugin>
  </plugins>
</pluginManagement>
1 Redefine value of propertyExpansion input property
2 Track contents of ${project.basedir}/custom-suppressions.xml as inputs ignoring the file name and the type of line endings

Disabling build caching for a plugin or execution

You can disable caching on a fine-grained level in the <pluginManagement> section of your pom.xml file. The following will disable caching for all executions of the failsafe plugin in the given project:

Using the Programmatic configuration (Maven extension v1.15+)
buildCache.registerMojoMetadataProvider(context -> {
    context.withPlugin("maven-failsafe-plugin",
        () -> context.outputs(outputs -> outputs.notCacheableBecause("these tests verify integration with other systems and should rerun even if our inputs didn't change"))
    );
});
<pluginManagement>
  <plugins>
    <plugin>
      <groupId>com.gradle</groupId>
      <artifactId>gradle-enterprise-maven-extension</artifactId>
      <configuration>
        <gradleEnterprise>
          <plugins>
            <plugin>
              <artifactId>maven-failsafe-plugin</artifactId>
              <outputs>
                <notCacheableBecause>these tests verify integration with other systems and should rerun even if our inputs didn't change</notCacheableBecause>
              </outputs>
            </plugin>
          </plugins>
        </gradleEnterprise>
      </configuration>
    </plugin>
  </plugins>
</pluginManagement>

You can also disable caching for a specific execution. Other executions of that plugin will then still remain cacheable. The following will disable caching only for the systems-integration-test execution of the failsafe plugin. Other tests will remain cacheable.

Using the Programmatic configuration (Maven extension v1.15+)
buildCache.registerMojoMetadataProvider(context -> {
    context.withPlugin("maven-failsafe-plugin", () -> {
            if ("systems-integration-test".equals(context.getMojoExecution().getExecutionId())) {
                context.outputs(outputs -> outputs.notCacheableBecause("these tests verify integration with other systems and should rerun even if our inputs didn't change"));
            }
        }
    );
});
<pluginManagement>
  <plugins>
    <plugin>
      <groupId>com.gradle</groupId>
      <artifactId>gradle-enterprise-maven-extension</artifactId>
      <configuration>
        <gradleEnterprise>
          <plugins>
            <plugin>
              <artifactId>maven-failsafe-plugin</artifactId>
              <executions>
                <execution>
                  <id>systems-integration-test</id>
                  <outputs>
                    <notCacheableBecause>these tests verify integration with other systems and should rerun even if our inputs didn't change</notCacheableBecause>
                  </outputs>
                </execution>
              </executions>
            </plugin>
          </plugins>
        </gradleEnterprise>
      </configuration>
    </plugin>
  </plugins>
</pluginManagement>

Disabling storing outputs for a specific goal or execution

(Maven extension 1.14.3+)

By default, outputs are stored in the Build Cache if it is enabled and the build includes the clean lifecycle phase. Disabling storing outputs of a specific goal can be achieved by setting the storeEnabled option to false on the outputs configuration of the goal’s plugin or execution.

Using the Programmatic configuration (Maven extension v1.15+)
buildCache.registerMojoMetadataProvider(context -> {
    context.withPlugin("maven-compiler-plugin", () -> context.outputs(outputs -> outputs.storeEnabled(false)));
});
<pluginManagement>
  <plugins>
    <plugin>
      <groupId>com.gradle</groupId>
      <artifactId>gradle-enterprise-maven-extension</artifactId>
      <configuration>
        <gradleEnterprise>
          <plugins>
            <plugin>
              <artifactId>maven-compiler-plugin</artifactId>
              <outputs>
                <storeEnabled>false</storeEnabled>
              </outputs>
            </plugin>
          </plugins>
        </gradleEnterprise>
      </configuration>
    </plugin>
  </plugins>
</pluginManagement>

An example use case is when local development has the side effect of corrupting outputs of a goal (e.g. when the IDE and Maven use the same compilation output directory). Without disabling storing outputs to the Build Cache, this can lead to issues with corrupt cache entries being loaded which make downstream goals fail (to resolve such a situation you can use the -DrerunGoals command line argument). To avoid this situation, the above sample configuration for the compile goal disables storing its outputs in a local-only enabled Maven profile. On CI, outputs will still be stored in the Build Cache so that local developer builds are able to reuse cache entries from prior CI builds.

The following example shows how to configure the local profile to disable storing outputs generated by the compile goal. To check if the build is executed locally we check that the environment variable CI is not set.

Using the Programmatic configuration (Maven extension v1.15+)
buildCache.registerMojoMetadataProvider(context -> {
    context.withPlugin("maven-compiler-plugin", () -> {
        if (!Boolean.parseBoolean(System.getenv("CI"))) {
            context.outputs(outputs -> outputs.storeEnabled(false));
        }
    });
});
<profiles>
  <profile>
    <id>local</id>
    <activation>
      <property>
        <name>!env.CI</name>
      </property>
    </activation>
    <build>
      <pluginManagement>
        <plugins>
          <plugin>
            <groupId>com.gradle</groupId>
            <artifactId>gradle-enterprise-maven-extension</artifactId>
            <configuration>
              <gradleEnterprise>
                <plugins>
                  <plugin>
                    <artifactId>maven-compiler-plugin</artifactId>
                    <outputs>
                      <storeEnabled>false</storeEnabled>
                    </outputs>
                  </plugin>
                </plugins>
              </gradleEnterprise>
            </configuration>
          </plugin>
        </plugins>
      </pluginManagement>
    </build>
  </profile>
</profiles>

Conditionally skipping a goal execution

(Maven extension 1.15+)

You can conditionally skip a goal execution by configuring the skipIfTrue option with one or several Mojo properties of type boolean. If the value of any configured property is true, then the goal execution will be skipped.

Using the Programmatic configuration (Maven extension v1.15+)
buildCache.registerMojoMetadataProvider(context -> {
    context.withPlugin("maven-enforcer-plugin", () -> {
        context.skipIfTrue("skip"); (1)
        if ("enforce-banned-dependencies".equals(context.getMojoExecution().getExecutionId())) {
            context.skipIfTrue("skip"); (2)
        }
    });
});
<pluginManagement>
  <plugins>
    <plugin>
      <groupId>com.gradle</groupId>
      <artifactId>gradle-enterprise-maven-extension</artifactId>
      <configuration>
        <gradleEnterprise>
          <plugins>
            <plugin>
              <groupId>org.apache.maven.plugins</groupId>
              <artifactId>maven-enforcer-plugin</artifactId>
              <skipIfTrue>
                <property>skip</property> (1)
              </skipIfTrue>
              <executions>
                <execution>
                  <id>enforce-banned-dependencies</id>
                  <skipIfTrue>
                    <property>skip</property> (2)
                  </skipIfTrue>
                </execution>
              </executions>
            </plugin>
          </plugins>
        </gradleEnterprise>
      </configuration>
    </plugin>
  </plugins>
</pluginManagement>
1 Will skip all executions of maven-enforcer-plugin if skip property is set
2 Will skip only specific execution of maven-enforcer-plugin if skip property is set

An example use case is a goal that supports skipping of its execution via setting a specific boolean property. Even if a goal execution is skipped via such a property, the Build Cache will still attempt to retrieve outputs from a previous execution. In order to avoid unnecessary computation and network overhead, the name of the specific boolean property can be declared via skipIfTrue.

All the supported goals are already configured to skip the Build Cache if the goal is skipped.

Making other goals cacheable

The extension allows you to make any goal cacheable, beyond the ones that are supported out of the box. Take great care to define all of the goal’s inputs and outputs before doing so, to avoid false cache hits and follow-up errors.

When making goals cacheable, you don’t need to repeat the values of all their inputs and outputs. You can simply provide the name of each property and the extension will look up the value in the goal’s configuration. The extension will make sure that you have handled all configuration parameters of the goal in this way. If some parameter is irrelevant for the purposes of caching, e.g. because it only affects console output, you can tell the extension to ignore it.

For input properties, the extension supports all primitives, Strings, Enums and Collections, Arrays and Maps of those. Any other types need to be broken down using the nestedProperties (for a single complex type) or iteratedProperties (for a Collection of complex types) configuration.

Using the Programmatic configuration (Maven extension v1.15+)
buildCache.registerMojoMetadataProvider(context -> {
    context.withPlugin("awesome-but-slow-plugin", () -> {
            if ("my.company".equals(context.getMojoExecution().getPlugin().getGroupId())) {
                context.inputs(inputs -> inputs
                        .fileSet("sources", fileSet -> fileSet.includesProperty("includes").excludesProperty("excludes"))
                        .properties("encoding")
                        .ignore("logWarnings")
                    )
                    .nested("forkOptions", nestedContext -> nestedContext.inputs(inputs -> inputs.properties("maxHeap")))
                    .iterate("targetPlatforms", iteratedContext -> iteratedContext.inputs(inputs -> inputs.properties("architecture", "linkingMode")))
                    .outputs(outputs -> outputs.directory("outputDir").cacheable("This plugin has CPU-bound goals with well-defined inputs and outputs"));
            }
        }
    );
});
<pluginManagement>
  <plugins>
    <plugin>
      <groupId>com.gradle</groupId>
      <artifactId>gradle-enterprise-maven-extension</artifactId>
      <configuration>
        <gradleEnterprise>
          <plugins>
            <plugin>
              <groupId>my.company</groupId>
              <artifactId>awesome-but-slow-plugin</artifactId>
              <inputs>
                <fileSets>
                  <fileSet>
                    <name>sources</name>
                    <includesProperty>includes</includesProperty>
                    <excludesProperty>excludes</excludesProperty>
                  </fileSet>
                </fileSets>
                <properties>
                  <property>
                    <name>encoding</name>
                  </property>
                </properties>
                <ignoredProperties>
                  <ignore>logWarnings</ignore>
                </ignoredProperties>
              </inputs>
              <nestedProperties>
                <property>
                  <name>forkOptions</name>
                  <inputs>
                    <properties>
                      <property>
                        <name>maxHeap</name>
                      </property>
                    </properties>
                  </inputs>
                </property>
              </nestedProperties>
              <iteratedProperties>
                <property>
                  <name>targetPlatforms</name>
                  <inputs>
                    <properties>
                      <property>
                        <name>architecture</name>
                      </property>
                      <property>
                        <name>linkingMode</name>
                      </property>
                    </properties>
                  </inputs>
                </property>
              </iteratedProperties>
              <outputs>
                <directories>
                  <directory>
                    <name>outputDir</name>
                  </directory>
                </directories>
                <cacheableBecause>this plugin has CPU-bound goals with well-defined inputs and outputs</cacheableBecause>
              </outputs>
            </plugin>
          </plugins>
        </gradleEnterprise>
      </configuration>
    </plugin>
  </plugins>
</pluginManagement>

Troubleshooting

While working with the Build Cache you may encounter situations where build results are not retrieved from the Build Cache, although you would expect them to. This section provides guidance for analyzing and solving these problems.

Debugging cache operations

The extension provides several loggers to make analyzing problems with build caching easier. To show the effective Build Cache configuration, use the gradle.goal.cache logger:

$ mvn clean verify -Dorg.slf4j.simpleLogger.log.gradle.goal.cache=debug
[DEBUG] Using the Build Cache with the following configuration:
  Local Build Cache: enabled
      directory: /Users/johndoe/.m2/.gradle-enterprise/build-cache
      cleanup: enabled
          retention: 168h
          interval: 24h
  Remote Build Cache: enabled
      url: https://my-server/cache/
      authenticated: false
      storeEnabled: false
      allowUntrustedServer: false
      useExpectContinue: false

The gradle.goal.cache logger will also print the result of determining the cacheability of the executed goals:

[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ maven-build-scan-extension-sample ---
[INFO] skip non existing resourceDirectory /Users/johndoe/workspace/maven-build-scan-quickstart/src/main/resources
[DEBUG] Build caching was not enabled for this goal execution because the 'resources' goal was not supported.
[INFO]
[INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ maven-build-scan-extension-sample ---
[DEBUG] Local cache miss
[DEBUG] Remote cache miss
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 1 source file to /Users/johndoe/workspace/maven-build-scan-quickstart/target/classes
[DEBUG] Stored outputs in the local Build Cache

All information printed by the gradle.goal.cache can also be viewed in the build scan for that build.

Finding the cause of cache misses

Sometimes you might encounter a situation where a goal execution is not avoided by using the Build Cache although you would expect it to be. For example, if you run the same build twice without any changes, the outputs of all supported goals should be retrieved from the local Build Cache (if it is enabled). If this is not the case, this almost always is caused by unstable inputs, e.g. a timestamp being added to a file by some build logic. In order to identify which inputs change between builds the Maven build comparison feature can be used. Simply run the same Maven build twice and compare those two builds. To make it easier to find unstable input files capturing of goal input files should be explicitly enabled using -Dgradle.scan.captureGoalInputFiles=true

Capturing goal input files has an impact on build performance. For this reason it is disabled by default.

Once the build scans have been published they can be compared in Develocity. In this example, the build was configured to write a timestamp to the build.properties file. When comparing the two builds this shows up nicely in the comparison.

comparison unstable input

Once the changing input is identified, the build can be changed to be reproducable or normalization can be used to ignore the changing input.

Solving common causes of cache misses

Some widely used Maven plugins are a common cause of cache misses because they produce changing build results. This chapter shows you how to solve them.

JAXB

Old versions of the XJC binding compiler generate classes with methods in random order on each invocation. This has been fixed in JAXB 2.2.11. Since there are several Maven plugins available for JAXB, you need to find out which release of the plugin you are using includes the fixed JAXB release. For example the jaxb2-maven-plugin includes the fix starting from release 2.1.

Another cause of unstable build results when using JAXB is the fact that the XJC binding compiler generates a header containing a timestamp into all Java classes. This behavior is controlled by the --no-header option which is false by default (= always generate a header). To prevent this add the corresponding configuration to the Maven plugin you use, for example:

<plugin>
  <groupId>org.codehaus.mojo</groupId>
  <artifactId>jaxb2-maven-plugin</artifactId>
  <version>2.4</version>
  <configuration>
    <noGeneratedHeaderComments>true</noGeneratedHeaderComments>
  </configuration>
</plugin>

If you’re using the maven-jaxb2-plugin it’s still a good idea to remove unnecessary instability from its outputs. However, the Develocity Maven Extension supports caching its generate goal even if file headers are being generated. Thus, downstream goals will not be affected by its changing outputs when they are loaded from the cache.

Some Maven JAXB plugins generate code based on the current system’s locale if not configured otherwise. This leads to unstable outputs depending on the configuration of the machine that executes the build, which in turn can lead to cache misses. For this reason the locale to use during code generation should be explicitly configured. Both the jaxb2-maven-plugin and the maven-jaxb2-plugin provide a <locale> option for this.

maven-bundle-plugin

Older versions of the maven-bundle-plugin generate a timestamp in the MANIFEST.MF file. To prevent this, use version 5.1.5+ of the plugin or adjust the plugin configuration as following:

<plugin>
  <groupId>org.apache.felix</groupId>
  <artifactId>maven-bundle-plugin</artifactId>
  <configuration>
    <archive>
      <addMavenDescriptor>false</addMavenDescriptor>
    </archive>
    <instructions>
      <_removeheaders>Bnd-LastModified</_removeheaders>
    </instructions>
  </configuration>
</plugin>

Note that the underscore in <_removeheaders> is not a typo.

maven-resources-plugin

A common pattern is to write a build timestamp to a build.properties file using Maven resource filtering. One way to fix this is using normalization to ignore the file. Alternatively the build can be adjusted by moving the generation of the timestamp to a separate profile that is only executed when creating a release:

build.properties
build.timestamp=${timestamp}
pom.xml
<properties>
  <timestamp>2019-03-07 12:00:00.000</timestamp>
</properties>

<build>
  <resources>
    <resource>
      <directory>src/main/resources</directory>
      <filtering>true</filtering>
    </resource>
  </resources>
</build>

<profile>
  <id>release</id>
  <properties>
    <maven.build.timestamp.format>yyyy-MM-dd HH:mm:ss.S</maven.build.timestamp.format>
    <timestamp>${maven.build.timestamp}</timestamp>
  </properties>
</profile>
maven-surefire-plugin
JAR file in test classpath

By default, the test runtime classpath used by the maven-surefire-plugin contains the classes directory of project dependencies if the build has been started with the mvn clean test command. If the build was started using mvn clean package or a later lifecycle phase, then, instead of the classes directory, the test runtime classpath will contain the JAR file. Such behavior might lead to unexpected cache misses.

To prevent such a situation you can configure the maven-jar-plugin to produce the JAR file before the test phase. For example by binding the default-jar execution to the process-test-resources phase:

pom.xml
<plugin>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-jar-plugin</artifactId>
  <executions>
    <execution>
      <id>default-jar</id>
      <phase>process-test-resources</phase>
    </execution>
  </executions>
</plugin>

Such a change will force the maven-surefire-plugin to always use the JAR file and will help to avoid cache misses.

Using with native-maven-plugin from GraalVM

Using the native-maven-plugin from org.graalvm.buildtools will prevent caching the output of the Surefire test goals. The native-maven-plugin will register an untracked output folder under target/test-ids which causes the goals to become uncacheable. To solve this, declare the folder as an output for the Surefire plugin in the configuration of the gradle-enterprise-maven-extension as follows:

pom.xml
<pluginManagement>
    <plugins>
        <plugin>
            <groupId>com.gradle</groupId>
            <artifactId>gradle-enterprise-maven-extension</artifactId>
            <configuration>
                <gradleEnterprise>
                    <plugins>
                        <plugin>
                            <artifactId>maven-surefire-plugin</artifactId>
                            <outputs>
                                <directories>
                                    <directory>
                                        <name>test-ids</name>
                                        <path>${project.build.directory}/test-ids</path>
                                    </directory>
                                </directories>
                            </outputs>
                        </plugin>
                    </plugins>
                </gradleEnterprise>
            </configuration>
        </plugin>
    </plugins>
</pluginManagement>
Using system properties

When the maven-surefire-plugin is used with <systemPropertyVariables> defined in the plugin’s configuration, if any of the defined properties contain a path, this path must be declared as an extra input/output parameter on the gradle-enterprise-plugin’s `surefire-plugin related configuration. When the paths are not declared the task will not be cacheable and the goal’s cacheability reason will display Goal execution marked as not cacheable: Build caching was not enabled for this goal execution because system property 'samplesDir' with value '$path' was used as a command line argument, but not declared as an input or output.

pom.xml
<build>
    <!-- ... -->
    <plugins>
        <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-surefire-plugin</artifactId>
        <version>3.1.0</version>
        <configuration>
            <systemPropertyVariables>
                <test.project.directory>${test.project.directory}</test.project.directory>
                <test.output.directory>${test.output.directory}</test.output.directory>
            </systemPropertyVariables>
        </configuration>
        </plugin>
    </plugins>

    <pluginManagement>
        <plugins>
            <plugin>
            <groupId>com.gradle</groupId>
            <artifactId>gradle-enterprise-maven-extension</artifactId>
            <configuration>
                <gradleEnterprise>
                <plugins>
                    <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-surefire-plugin</artifactId>
                    <inputs>
                        <fileSets>
                            <fileSet>
                                <name>generatedTestDir</name>
                                <paths>
                                  <path>${test.project.directory}</path>
                                </paths>
                            </fileSet>
                        </fileSets>
                    </inputs>
                    <outputs>
                        <directories>
                            <directory>
                                <name>testCacheDir</name>
                                <path>${test.output.directory}</path>
                            </directory>
                        </directories>
                    </outputs>
                    </plugin>
                </plugins>
                </gradleEnterprise>
            </configuration>
            </plugin>
        </plugins>
    </pluginManagement>
</build>

Alternatively normalization could be used to ignore certain system properties. Please refer to the system property normalization section of the extension user manual for details.

maven-failsafe-plugin

The maven-failsafe-plugin provides two goals: integration-test and verify. The former runs in the integration-test phase of the build and writes its results to a summary file. The latter runs in the verify phase, reads the summary file, and fails the build in case of test failures.

When configuring multiple Failsafe executions, they use the same output location for the summary file by default. This will prevent all but the first execution of the integration-test goal to be cacheable due to overlapping outputs. In order to get cache hits for all executions, you should configure a different summary file for each of them:

pom.xml
<plugin>
  <artifactId>maven-failsafe-plugin</artifactId>
  <executions>
    <execution>
      <id>first-execution</id>
      <goals>
        <goal>integration-test</goal>
        <goal>verify</goal>
      </goals>
      <configuration>
        <!-- ... -->
        <summaryFile>${project.build.directory}/failsafe-reports/first-failsafe-summary.xml</summaryFile>
      </configuration>
    </execution>
    <execution>
      <id>second-execution</id>
      <goals>
        <goal>integration-test</goal>
        <goal>verify</goal>
      </goals>
      <configuration>
        <!-- ... -->
        <summaryFile>${project.build.directory}/failsafe-reports/second-failsafe-summary.xml</summaryFile>
      </configuration>
    </execution>
  </executions>
</plugin>

If you have configured multiple executions that execute the same or an overlapping set of test classes (e.g. with different parameters), you should in addition change the reports directory, for example:

pom.xml
<plugin>
  <artifactId>maven-failsafe-plugin</artifactId>
  <executions>
    <execution>
      <id>first-execution</id>
      <goals>
        <goal>integration-test</goal>
        <goal>verify</goal>
      </goals>
      <configuration>
        <!-- ... -->
        <reportsDirectory>${project.build.directory}/first-failsafe-reports</reportsDirectory>
        <summaryFile>${project.build.directory}/first-failsafe-reports/failsafe-summary.xml</summaryFile>
      </configuration>
    </execution>
    <execution>
      <id>second-execution</id>
      <goals>
        <goal>integration-test</goal>
        <goal>verify</goal>
      </goals>
      <configuration>
        <!-- ... -->
        <reportsDirectory>${project.build.directory}/second-failsafe-reports</reportsDirectory>
        <summaryFile>${project.build.directory}/second-failsafe-reports/failsafe-summary.xml</summaryFile>
      </configuration>
    </execution>
  </executions>
</plugin>
maven-compiler-plugin

When invoking the build without the clean lifecycle, the Build Cache is in read-only mode. Existing cache entries produced by earlier builds are then reused but no new entries are stored. This works for all Maven goals that are supported out of the box with the exception of the maven-compiler-plugin. Since the maven-compiler-plugin can be used in conjunction with other plugins that produce class files (e.g. when also using another JVM language like Kotlin or Groovy in the same project), it uses the classes output directory (usually target/classes) as an input. Therefore, builds without clean will have different inputs and thus a different cache key.

Use pom.xml merge strategies to solve misconfigurations

When there is a pom.xml configuration for the Gradle Enterprise Maven extension (e.g. runtime classpath normalization or declaring inputs and outputs for given plugins) on a parent pom.xml and another configuration on a child pom.xml, it can happen that the given configurations are merged incorrectly, resulting in a misconfiguration of the Gradle Enterprise Maven extension. To see the effective pom.xml that is used during the execution of the build on any given project mvn help:effective-pom can be executed, and the effective pom.xml is printed to the console. If a check of the Gradle Enterprise Maven extension configuration shows that it’s invalid or not properly merged, then a different merge strategy can be applied as mentioned in this blog post.

In this example we have a parent project and a child project which both have specific Gradle Enterprise configurations for the compiler and Surefire mojos. The following excerpt is from the parent pom.xml:

<pluginManagement>
  <plugins>
    <plugin>
      <groupId>com.gradle</groupId>
      <artifactId>gradle-enterprise-maven-extension</artifactId>
      <version>1.20.1</version>
      <configuration>
        <gradleEnterprise>
          <plugins>
            <plugin>
              <groupId>org.apache.maven.plugins</groupId>
              <artifactId>maven-compiler-plugin</artifactId>
              <executions>
                <execution>
                  <id>default-compile</id>
                  <outputs>
                    <notCacheableBecause>something</notCacheableBecause> (1)
                  </outputs>
                </execution>
              </executions>
            </plugin>
            <plugin>
              <groupId>org.apache.maven.plugins</groupId>
              <artifactId>maven-surefire-plugin</artifactId>
              <inputs>
                <properties>
                  <property>
                    <name>additionalProperty</name> (2)
                    <value>${additionalProperty}</value>
                  </property>
                </properties>
              </inputs>
            </plugin>
          </plugins>
        </gradleEnterprise>
      </configuration>
    </plugin>
  </plugins>
</pluginManagement>
1 Parent POM configures compiler mojo to be not cacheable
2 Parent POM configures Surefire mojo to track an additionalProperty as input

This excerpt is from the child pom.xml where we want to keep the configuration of the compiler mojo defined on the parent pom.xml and add another property as input to the Surefire mojo:

<pluginManagement>
  <plugins>
    <plugin>
      <groupId>com.gradle</groupId>
      <artifactId>gradle-enterprise-maven-extension</artifactId>
      <version>1.20.1</version>
      <configuration>
        <gradleEnterprise>
          <plugins>
            <plugin>
              <groupId>org.apache.maven.plugins</groupId> (1)
              <artifactId>maven-compiler-plugin</artifactId>
            </plugin>
            <plugin>
              <groupId>org.apache.maven.plugins</groupId>
              <artifactId>maven-surefire-plugin</artifactId>
              <inputs>
                <properties combine.children="append">
                  <property>
                    <name>anotherAdditionalProperty</name> (2)
                    <value>${anotherAdditionalProperty}</value>
                  </property>
                </properties>
              </inputs>
            </plugin>
          </plugins>
        </gradleEnterprise>
      </configuration>
    </plugin>
  </plugins>
</pluginManagement>
1 Child POM configures to inherit compiler mojo configuration from parent POM
2 Child POM configures Surefire mojo to track an anotherAdditionalProperty as input

Due to the merging strategies available for Maven POM files there are several pitfalls:

  1. If a child POM file wants to inherit the configuration of a parent POM file, it needs to declare the same plugins in the exact same order as in the parent POM such that Maven properly merges the two POM files.

  2. If some elements of a parent POM need to be extended in a child POM, the above explained merges strategies should be taken into account. In the example child POM we use the combine.children="append" merge strategy to append the anotherAdditionalProperty input to the existing additionalProperty input declared on the parent POM.

With the above setup the merged child POM produced by retrieving the effective POM via executing mvn help:effective-pom resulted in the following merged child POM:

<pluginManagement>
  <plugins>
    <plugin>
      <groupId>com.gradle</groupId>
      <artifactId>gradle-enterprise-maven-extension</artifactId>
      <version>1.20.1</version>
      <configuration>
        <gradleEnterprise>
          <plugins>
            <plugin>
              <groupId>org.apache.maven.plugins</groupId>
              <artifactId>maven-compiler-plugin</artifactId>
              <executions>
                <execution>
                  <id>default-compile</id>
                  <outputs>
                    <notCacheableBecause>something</notCacheableBecause> (1)
                  </outputs>
                </execution>
              </executions>
            </plugin>
            <plugin>
              <groupId>org.apache.maven.plugins</groupId>
              <artifactId>maven-surefire-plugin</artifactId>
              <inputs>
                <properties combine.children="append"> (2)
                  <property>
                    <name>additionalProperty</name>
                    <value>${additionalProperty}</value>
                  </property>
                  <property>
                    <name>anotherAdditionalProperty</name>
                    <value>${anotherAdditionalProperty}</value>
                  </property>
                </properties>
              </inputs>
            </plugin>
          </plugins>
        </gradleEnterprise>
      </configuration>
    </plugin>
  </plugins>
</pluginManagement>
1 Merged child POM inherits the compiler mojo configuration from parent POM
2 Merged child POM configures Surefire mojo to track both properties as inputs

Rerunning goals to deal with invalid cache entries

In rare circumstances the Build Cache might be filled with an invalid entry, e.g. when another process deletes the outputs of a goal while the cache entry is being created. In this case you can use the -DrerunGoals command line argument to rerun the goals and overwrite the faulty cache entry.

Using Test Distribution

(Maven extension 1.8+, Develocity 2020.5+)

Develocity Test Distribution takes your existing test suites and distributes them across remote agents to execute them faster.

For information on how to use Test Distribution, please consult the Test Distribution User Manual.

Using Predictive Test Selection

(Maven extension 1.14+, Develocity 2022.2+)

Develocity Predictive Test Selection allows developers to get faster feedback by running only tests that are likely to provide useful feedback on a particular code change using a probabilistic machine learning model.

For information on how to use Predictive Test Selection, please consult the Predictive Test Selection User Manual.

Appendix A: Configuration reference

gradle-enterprise.xml

Most aspects of the Develocity Maven extension are configured in the gradle-enterprise.xml configuration file. Some options can be overwritten by system properties.

The gradle-enterprise.xml file can be put into several locations. These files are merged and their properties overwritten based on the precedence rules below:

  • <maven-home>/conf/gradle-enterprise.xml is used to set global defaults for a given Maven installation. This is useful when you ship a custom Maven distribution to your teams. The location of this configuration file can be overwritten using the -Dgradle.global.config argument. This can be useful for CI environments where changing the Maven installation is not possible.

  • <classpath>/gradle-enterprise.xml is used for organization-wide or team-wide configuration and overrides the global configuration. This allows to package a gradle-enterprise.xml file in the root of a custom extension jar that can be reused across projects.

  • <project-dir>/.mvn/gradle-enterprise.xml is used for project-specific configuration and overrides the classpath configuration.

  • <user-home>/.m2/gradle-enterprise.xml is used for user-specific configuration and overrides the project configuration. The location of this configuration file can be overwritten using the -Dgradle.user.config argument. This can be useful for CI environments where changing the user home is not possible.

The example below shows a full reference of everything you can configure in this file.

Be sure to include the XML namespace declarations to get auto-completion in your IDE. The latest version of the schema is available at https://www.gradle.com/schema/gradle-enterprise-maven.xsd, or you can get a specific schema version by appending the Develocity Maven extension version to the schema location, e.g. https://www.gradle.com/schema/gradle-enterprise-maven-1.20.1.xsd. IntelliJ IDEA will mark unknown schemas as missing and they have to be explicitly fetched via the quick fix dialog (Alt + Enter). There is an open issue to make this more user-friendly.

gradle-enterprise.xml
<gradleEnterprise
  xmlns="https://www.gradle.com/gradle-enterprise-maven" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="https://www.gradle.com/gradle-enterprise-maven https://www.gradle.com/schema/gradle-enterprise-maven.xsd">
  <!-- Whether the Develocity Maven extension should be enabled. Defaults to true. System property is 'gradle.enterprise.enabled'. -->
  <enabled>true</enabled>
  <!-- Project identifier to be sent to the Develocity server when build scan is published. System property is 'gradle.enterprise.projectId'. -->
  <projectId>myProject</projectId>
  <server>
    <!-- ID used to reference an element in the settings.xml. System property is 'gradle.enterprise.serverId'. -->
    <id>my-server</id>
    <!-- Address of the Develocity server. System property is 'gradle.enterprise.url'. -->
    <url>http://my-server/</url>
    <!-- Whether untrusted connections to the Develocity server should be accepted. Defaults to false. System property is 'gradle.enterprise.allowUntrustedServer'. -->
    <allowUntrusted>false</allowUntrusted>
    <!-- The access key (without any hostname prefix) for authenticating with the Develocity server. Environment variable is 'GRADLE_ENTERPRISE_ACCESS_KEY'. -->
    <accessKey>7w5kbqqjea4vonghohvuyra5bnvszop4asbqee3m3sm6dbjdudtq</accessKey>
  </server>
  <!-- Storage directory for caches and temporary data. Defaults to ${user.home}/.m2/.gradle-enterprise. System property is 'gradle.enterprise.storage.directory'. -->
  <storageDirectory>/some/location</storageDirectory>
  <buildScan>
    <!-- Behavior of publishing build scans. Possible values are ALWAYS, ON_FAILURE, ON_DEMAND. Defaults to ALWAYS. The 'scan' system property can be used to publish on demand. -->
    <publish>ALWAYS</publish>
    <!-- Terms of service acceptance (mandatory to publish to scans.gradle.com) -->
    <termsOfService>
      <!-- Address of the terms of service. Must be 'https://gradle.com/terms-of-service'. Defaults to an empty string. System property is 'gradle.scan.termsOfService.url'. -->
      <url></url>
      <!-- Signal acceptance of the terms of service. Must be 'true'. Defaults to false. System property is 'gradle.scan.termsOfService.accept'. -->
      <accept>false</accept>
    </termsOfService>
    <!-- Whether to upload the build scan in background. Defaults to true. System property is 'gradle.scan.uploadInBackground' -->
    <backgroundBuildScanUpload>false</backgroundBuildScanUpload>
    <!-- For extension < 1.11 - DEPRECATED: Whether to capture content hashes of each input file for build scan comparison. Defaults to false. System property is 'gradle.scan.captureGoalInputFiles' -->
    <captureGoalInputFiles>true</captureGoalInputFiles>
    <!-- For extension >= 1.11 -->
    <capture>
      <!-- Whether to capture content hashes of each input file for build scan comparison. Defaults to false. System property is 'gradle.scan.captureGoalInputFiles' -->
      <goalInputFiles>true</goalInputFiles>
      <!-- Whether to capture build output for build scans. Defaults to true. System property is 'gradle.scan.captureBuildLogging' -->
      <buildLogging>true</buildLogging>
      <!-- Whether to capture test output for build scans. Defaults to true. System property is 'gradle.scan.captureTestLogging' -->
      <testLogging>true</testLogging>
    </capture>
    <!-- Obfuscated values for captured build scan data (optional). -->
    <obfuscation>
      <!-- The obfuscated username to capture (optional). -->
      <username></username>
      <!-- The obfuscated hostname to capture for local and public hostnames (optional). -->
      <hostname></hostname>
      <!-- The obfuscated IP addresses to capture (optional). -->
      <ipAddresses></ipAddresses>
    </obfuscation>
    <!-- List of tags to capture. Additionally, system properties like 'scan.tag.<tag>' can be used to add tags. -->
    <tags>
      <tag>my tag</tag>
    </tags>
    <!-- List of links to capture. Additionally, system properties like 'scan.link.<name>=<url>' can be used to add links. -->
    <links>
      <link>
        <name>my link</name>
        <url>http://my-site.com</url>
      </link>
    </links>
    <!-- List of custom values to capture. Additionally, system properties like 'scan.value.<name>=<value>' can be used to add custom values. -->
    <values>
      <value>
        <name>my name</name>
        <value>my value</value>
      </value>
    </values>
  </buildScan>
  <buildCache>
    <!-- Local cache configuration -->
    <local>
      <!-- Whether the local cache is enabled. Defaults to true. System property is 'gradle.cache.local.enabled'. -->
      <enabled>true</enabled>
      <!-- Whether to store outputs in the local build cache (as opposed to only loading from it). Defaults to true. System property is 'gradle.cache.local.storeEnabled'. -->
      <storeEnabled>true</storeEnabled>
      <!-- Local cache directory. Defaults to ${user.home}/.m2/.gradle-enterprise/build-cache. System property is 'gradle.cache.local.directory'. -->
      <directory>/some/other/location</directory>
      <!-- Local cache cleanup configuration -->
      <cleanup>
        <!-- Whether local cache cleanup is enabled. Defaults to true. System property is 'gradle.cache.local.cleanup.enabled'. -->
        <enabled>true</enabled>
        <!-- Items in the cache that were not used in this period will be deleted. Defaults to P7D. System property is 'gradle.cache.local.cleanup.retention'. -->
        <retention>P30D</retention>
        <!-- Interval at which the cleanup occurs. Defaults to P1D. System property is 'gradle.cache.local.cleanup.interval'. -->
        <interval>P10D</interval>
      </cleanup>
    </local>
    <!-- Remote cache configuration -->
    <remote>
      <!-- Remote cache server configuration -->
      <server>
        <!-- Optionally use the ID of a server specified in your settings.xml to use its credentials. System property is 'gradle.cache.remote.serverId'. -->
        <id>remote-cache</id>
        <!-- URL of the remote cache. Defaults to ${gradle.enterprise.url}/cache/. System property is 'gradle.cache.remote.url'. -->
        <url>http://my-node/cache/</url>
        <!-- Optionally specify the credentials. The credentials specified here take precedence over the credentials in your settings.xml -->
        <credentials>
          <!-- The username to use to connect to an authenticated cache node. System property is 'gradle.cache.remote.username'. -->
          <username>some-username</username>
          <!-- The password to use to connect to an authenticated cache node. System property is 'gradle.cache.remote.password'. -->
          <password>some-password</password>
        </credentials>
        <!-- Whether the remote cache accepts untrusted connections. Defaults to false. System property is 'gradle.cache.remote.allowUntrustedServer'. -->
        <allowUntrusted>true</allowUntrusted>
        <!-- Whether the client should enforce the use of HTTPS. Setting it to true will enable the usage of unencrypted HTTP. System property is 'gradle.cache.remote.allowInsecureProtocol'. -->
        <allowInsecureProtocol>true</allowInsecureProtocol>
        <!-- Whether the client should use HTTP Expect-Continue (https://www.w3.org/Protocols/rfc2616/rfc2616-sec8.html#sec8.2.3) when storing data on the server. System property is 'gradle.cache.remote.useExpectContinue'. -->
        <useExpectContinue>true</useExpectContinue>
      </server>
      <!-- Whether the remote cache is enabled. Defaults to true. System property is 'gradle.cache.remote.enabled'. -->
      <enabled>true</enabled>
      <!-- Whether to store outputs in the remote build cache (as opposed to only loading from it). Defaults to false. System property is 'gradle.cache.remote.storeEnabled'. -->
      <storeEnabled>true</storeEnabled>
    </remote>
    <!-- Whether the 'clean' lifecycle phase is required in order to store outputs in the build cache. Defaults to true. System property is 'gradle.cache.requireClean'. -->
    <!-- You should only set this to 'false' when the build is started from a clean working directory. Otherwise, produced build cache entries may be incorrect. -->
    <requireClean>true</requireClean>
  </buildCache>
</gradleEnterprise>

Expression support

The gradle-enterprise.xml configuration file supports two types of expressions that are evaluated when reading the configuration file:

${…​}

Maven-style expression (behaves like in pom.xml) for simple use cases, e.g. referencing an environment variable (e.g. ${env.CACHE_USERNAME})

#{…​}

Spring Expression Language (SpEL) expressions for more complex use cases, e.g. converting an environment variable into a boolean (e.g. #{env['CI'] == null})

For both expression types, the following objects can be referenced:

session

the current MavenSession object (e.g. ${session.request.cacheNotFound} or #{session.request.cacheNotFound})

basedir

the base directory of the build (e.g. ${basedir/src} or #{basedir}/src)

In addition, the following objects and functions can be referenced in SpEL expressions:

properties: Properties

user/system/profile properties (e.g. #{properties['user.dir']}). These are the same properties you can reference using the ${«property-name»} syntax.
User properties are passed via -D on the command-line. System properties are provided by the runtime and contain System.getProperties() as well as env.-prefixed environment variables. Profile properties refer to properties defined in active Maven profiles.

env: Map<String, String>

environment variables (e.g. #{env['CI']})

username: String

The username of the agent running the build (e.g. #{username})

ipAddresses: List<String>

The IP addresses of the agent running the build (e.g. #{ipAddresses})

isTrue(Object): boolean

returns true unless the supplied object’s String value case-insensitively equals false, 0, 0.0, or null (e.g. #{isTrue(true)})

isFalse(Object): boolean

returns true if the supplied object’s String value case-insensitively equals false, 0, 0.0, or null (e.g. #{isFalse(false)})

sha512(Object): Object

returns a SHA-512 String representation of the supplied object’s String value. If the supplied object is a List, returns a list of the individual sha512 call for each item of the list.

The following example shows how to use both expression types to configure local and CI builds with a single gradle-enterprise.xml file. It uses the JENKINS_URL environment variable (which is present in builds on Jenkins) to determine whether the build is running locally or on CI. Based on that, it enables the local Build Cache and background build scan upload only for local builds but enables writing to the remote Build Cache only for CI builds. Moreover, it determines the URL of the remote Build Cache based on the fictional REGION environment variable. Lastly, it uses Maven-style expressions to configure the remote Build Cache credentials based on custom environment variables that are typically injected by the CI server.

gradle-enterprise.xml
<gradleEnterprise
  xmlns="https://www.gradle.com/gradle-enterprise-maven" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="https://www.gradle.com/gradle-enterprise-maven https://www.gradle.com/schema/gradle-enterprise-maven.xsd">
  <buildScan>
    <backgroundBuildScanUpload>#{env['JENKINS_URL'] == null}</backgroundBuildScanUpload>
    <obfuscation>
      <username>#{sha512(username)}</username>
      <hostname>#{isTrue(env['CI']) ? 'CI agent' : 'Local agent'}</hostname>
      <ipAddresses>#{sha512(ipAddresses)}</ipAddresses>
    </obfuscation>
  </buildScan>
  <buildCache>
    <local>
      <enabled>#{env['JENKINS_URL'] == null}</enabled>
    </local>
    <remote>
      <server>
        <url>#{env['REGION'].startsWith('us') ? 'https://us.example.org/cache' : 'https://eu.example.org/cache'}</url>
        <credentials>
          <username>${env.GRADLE_ENTERPRISE_CACHE_USERNAME}</username>
          <password>${env.GRADLE_ENTERPRISE_CACHE_PASSWORD}</password>
        </credentials>
      </server>
      <enabled>true</enabled>
      <storeEnabled>#{env['JENKINS_URL'] != null}</storeEnabled>
    </remote>
  </buildCache>
</gradleEnterprise>

pom.xml

The Develocity Maven extension also allows you to configure module-specific aspects in the corresponding pom.xml file. This allows you to share common configuration between your project by putting it in a parent POM. See the example below for a full reference.

In order to get auto-completion in your IDE, be sure to include the XML namespace and schema location as shown in the example below. The latest version of the schema is always available at https://www.gradle.com/schema/gradle-enterprise-maven-project.xsd, or you can get a specific schema version by appending the Develocity Maven extension version to the schema location, e.g. https://www.gradle.com/schema/gradle-enterprise-maven-project-1.20.1.xsd. IntelliJ IDEA will mark unknown schemas as missing and they have to be explicitly fetched via the quick fix dialog (Alt + Enter). There is an open issue to make this more user-friendly. Please note that auto-completion is currently only supported by Eclipse. For IntelliJ IDEA, there’s an open issue to add such a feature.

pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd
        https://www.gradle.com/gradle-enterprise-maven-project https://www.gradle.com/schema/gradle-enterprise-maven-project.xsd">

  <!-- other build configuration -->
  <build>
    <pluginManagement>
      <plugins>
        <plugin>
          <groupId>com.gradle</groupId>
          <artifactId>gradle-enterprise-maven-extension</artifactId>
          <configuration>
            <gradleEnterprise xmlns="https://www.gradle.com/gradle-enterprise-maven-project">
              <normalization>
                <runtimeClassPath>
                  <ignoredFiles>
                    <ignoredFile>META-INF/build.properties</ignoredFile>
                  </ignoredFiles>
                  <propertiesNormalizations>
                    <propertiesNormalization>
                      <path>com/example/**/build.properties</path>
                      <ignoredProperties>
                        <ignore>build.timestamp</ignore>
                      </ignoredProperties>
                    </propertiesNormalization>
                  </propertiesNormalizations>
                  <metaInf>
                    <ignoreManifest>true</ignoreManifest>
                    <ignoreCompletely>true</ignoreCompletely>
                    <ignoredAttributes>
                      <ignore>Implementation-Version</ignore>
                    </ignoredAttributes>
                    <ignoredProperties>
                      <ignore>app.version</ignore>
                    </ignoredProperties>
                  </metaInf>
                </runtimeClassPath>
              </normalization>
              <plugins>
                <!-- an example of adding more details to an already cacheable plugin -->
                <plugin>
                  <artifactId>maven-failsafe-plugin</artifactId>
                  <inputs>
                    <fileSets>
                      <fileSet>
                        <name>samples</name>
                        <paths>
                          <path>src/test/samples</path>
                        </paths>
                        <includes>
                          <include>**/*.sample</include>
                        </includes>
                        <excludes>
                          <exclude>archive/**/*.sample</exclude>
                        </excludes>
                        <normalization>NAME_ONLY</normalization>
                      </fileSet>
                      <fileSet>
                        <name>config</name>
                        <paths>
                          <path>src/main/config</path>
                        </paths>
                        <normalization>
                          <strategy>RELATIVE_PATH</strategy>
                          <ignoreEmptyDirectories>true</ignoreEmptyDirectories>
                          <ignoreLineEndings>true</ignoreLineEndings>
                        </normalization>
                      </fileSet>
                    </fileSets>
                  </inputs>
                  <outputs>
                    <files>
                      <file>
                        <name>summary</name>
                        <path>target/test-results/summary.txt</path>
                      </file>
                    </files>
                    <directories>
                      <directory>
                        <name>screenshots</name>
                        <path>target/test-results/screenshots</path>
                      </directory>
                    </directories>
                    <notCacheableBecause>these tests verify integration with other systems and should rerun even if our
                      inputs didn't change
                    </notCacheableBecause>
                  </outputs>
                  <localState>
                    <fileSets>
                      <fileSet>
                        <name>someTemporaryStuff</name>
                        <paths>
                          <path>target/myTestFramework/tmp</path>
                        </paths>
                      </fileSet>
                    </fileSets>
                  </localState>
                </plugin>
                <plugin>
                  <artifactId>maven-compiler-plugin</artifactId>
                  <executions>
                    <execution>
                      <id>default-compile</id>
                      <inputs>
                        <!-- same as above -->
                      </inputs>
                      <outputs>
                        <!-- same as above -->
                      </outputs>
                      <localState>
                        <!-- same as above -->
                      </localState>
                    </execution>
                  </executions>
                </plugin>
                <!-- an example of making a custom plugin cacheable -->
                <plugin>
                  <groupId>my.company</groupId>
                  <artifactId>awesome-but-slow-plugin</artifactId>
                  <inputs>
                    <fileSets>
                      <fileSet>
                        <name>sources</name>
                        <includesProperty>includes</includesProperty>
                        <excludesProperty>excludes</excludesProperty>
                      </fileSet>
                    </fileSets>
                    <properties>
                      <property>
                        <name>encoding</name>
                      </property>
                    </properties>
                    <ignoredProperties>
                      <ignore>logWarnings</ignore>
                    </ignoredProperties>
                  </inputs>
                  <nestedProperties>
                    <property>
                      <name>forkOptions</name>
                      <inputs>
                        <properties>
                          <property>
                            <name>maxHeap</name>
                          </property>
                        </properties>
                      </inputs>
                    </property>
                  </nestedProperties>
                  <iteratedProperties>
                    <property>
                      <name>targetPlatforms</name>
                      <inputs>
                        <properties>
                          <property>
                            <name>architecture</name>
                          </property>
                          <property>
                            <name>linkingMode</name>
                          </property>
                        </properties>
                      </inputs>
                    </property>
                  </iteratedProperties>
                  <outputs>
                    <directories>
                      <directory>
                        <name>outputDir</name>
                      </directory>
                    </directories>
                    <cacheableBecause>this plugin has CPU-bound goals with well-defined inputs and outputs</cacheableBecause>
                  </outputs>
                  <localState>
                    <fileSets>
                      <fileSet>
                        <name>tempDir</name>
                      </fileSet>
                    </fileSets>
                  </localState>
                </plugin>
              </plugins>
              <buildScan>
                <tags>
                  <tag>my tag</tag>
                </tags>
                <links>
                  <link>
                    <name>my link</name>
                    <url>http://my-site.com</url>
                  </link>
                </links>
                <values>
                  <value>
                    <name>Build Number</name>
                    <value>${project.buildNumber}</value>
                  </value>
                </values>
              </buildScan>
            </gradleEnterprise>
          </configuration>
        </plugin>
      </plugins>
    </pluginManagement>
  </build>
</project>

Programmatic configuration

In order to access the Develocity Maven extension API to perform programmatic configuration of build scans and the Build Cache you need to create a Maven extension. The Common Custom User Data Maven Extension provided by Gradle Inc. provides an example. This extension can be applied directly to your project, or can serve as a template project for your own extension implementation.

Please see the API reference for more details.

Appendix B: Captured information

The Develocity Maven extension captures information while the build is running and transmits it to a server after the build has completed.

Most of the information captured can be considered to be build data. This includes the name of the projects in your build, the executed goals, plugins and other things of this nature. Some more general environmental information is also captured. This includes your Java version, operating system, hardware, country, timezone and other things of this nature.

Notably, the actual source code being built and the output artifacts are not captured. However, error messages emitted by compilers or errors in tests may reveal aspects of the source code.

Listing

The list below details the notable information captured by the Develocity Maven extension and transmitted in a build scan.

  • Environment

    • User home (system property 'user.home')

    • Maven home (system property 'maven.home')

    • Username (system property 'user.name') (Can be obfuscated)

    • Local hostname (environment variable 'COMPUTERNAME' / 'HOSTNAME') (Can be obfuscated)

    • Public hostname (Can be obfuscated)

    • Local IP addresses (Can be obfuscated)

    • Build Java Virtual Machine

    • Operating System

    • Hardware

  • Build

    • Build invocation options (e.g. requested phases and goals, switches)

    • Build console output

    • Build failure exception messages and stacktraces

    • Projects and structure

    • Executed goals

    • Executed tests (using Apache Maven Surefire plugin)

    • Resolved dependencies

    • Applied extensions

    • Applied plugins

    • Network downloads (performed by Maven)

    • Build Cache configuration

    • Background build scan publication

    • Maven Build Cache extension cache report

Access

Build scans published to a Develocity installation are viewable by all users that can reach the server and have the required roles, should Identity Access Management (IAM) be turned on. Develocity provides a search interface for discovering and finding individual build scans.

Build scans published to scans.gradle.com are viewable by anyone with the link assigned when publishing the build scan. Links to individual build scans are not discoverable and cannot be guessed, but may be shared.

Appendix C: Cacheable plugins and goals

The extension caches the following plugins and goals out of the box. Unless otherwise noted, all their parameters are tracked as part of the cache key.

More build cache configurations for additional Maven plugins, which are not supported out of the box by Develocity, can be viewed here.

maven-compiler-plugin

Supported versions: 3.1 and above

Supported goals:

  • compile

  • testCompile

Caching is automatically disabled if:

  • a non-javac toolchain is used

The following use cases currently require disabling the Build Cache for this plugin:

  • using annotation processors that read files outside of Maven’s resource directories

  • using annotation processors that generate sources outside of Maven’s generated sources directory

  • using any non-deterministic annotation processors

Compile avoidance

Unless there are annotation processors on the classpath, the extension uses compile avoidance so your sources are only recompiled if the signatures of the classes on the compile classpath have changed.

maven-surefire-plugin and maven-failsafe-plugin

Supported versions: 2.12.4 and above for Build Cache, 2.15 (except for 2.19 to 2.20.1) and above for Build Scans, 2.22.2 and above for Test Distribution and Predictive Test Selection.

Supported goals:

  • surefire:test

  • failsafe:integration-test

Caching is automatically disabled if:

Test results for surefire:test are stored in the Build Cache whenever the goal succeeds. Thus, by default, only successful or skipped test results are cached. However, if <testFailureIgnore> is set to true, test failures are cached as well.

The following use cases currently require disabling the Build Cache for these plugins:

  • non-deterministic tests (e.g. tests with random parameters)

  • tests that read files that are not on the test classpath (e.g. new File("src/test/samples"))

  • tests that write additional results that you absolutely need (e.g. screenshots for failed UI tests)

  • tests that read environment variables that are not explicitly declared using the <environmentVariables> property

  • tests that use Java agents that read additional inputs or create additional outputs, except for JaCoCo, which is explicitly supported

The following properties are deliberately not tracked as inputs, because they should not influence the test result:

  • all concurrency settings, e.g. <threadCount>

  • user properties (passed via -D to Maven) that are not declared in the goal configuration using <systemPropertyVariables>, <systemProperties>, or <argLine>.

If a user property (e.g. -Dmy.custom.property=someValue) influences the outcome or behavior of tests, it should be tracked as an input by declaring it explicitly:

pom.xml
<plugin>
  <artifactId>maven-surefire-plugin</artifactId>
  <configuration>
    <systemPropertyVariables>
      <my.custom.property>${my.custom.property}</my.custom.property>
    </systemPropertyVariables>
  </configuration>
</plugin>

jacoco-maven-plugin

Supported versions: 0.5 and above

Supported goals:

  • none of JaCoCo’s own goals are cached

  • surefire and failsafe remain cacheable when JaCoCo is used

The JaCoCo plugin hooks into surefire and failsafe as a Java agent, or can preemptively instrument classes when used in 'offline' mode. The extension automatically tracks all JaCoCo agent options (and the jacoco-agent.destfile system property for Maven extension 1.16.2+), when determining the cache key for surefire and failsafe tests. The JaCoCo execution data file is cached as an additional output of the test execution.

Caching is automatically disabled if:

To allow tests to be cached while using JaCoCo, have each surefire/failsafe execution write to a separate data file and use a jacoco:merge or jacoco:report-aggregate goal to create a merged data file or an aggregated report.

maven-jaxb2-plugin/jaxb-maven-plugin (org.jvnet.jaxb2.maven2/org.jvnet.jaxb)

Supported plugin artifact ids:

  • maven-jaxb2-plugin

  • maven-jaxb20-plugin

  • maven-jaxb21-plugin

  • maven-jaxb22-plugin

  • maven-jaxb23-plugin

  • jaxb-maven-plugin

Supported versions: 0.12.3 and above

Supported goals:

  • generate

Caching is automatically disabled if:

  • a non-local URL is used to declare a catalog, schema, or binding

The following use cases currently require disabling the Build Cache for these plugins:

  • non-local URL references to schemas or bindings with changing content from within schema or binding files

The following properties are deliberately not tracked as inputs, because they should not influence the result of code generation:

  • logging settings (verbose)

  • proxy settings (proxyHost, proxyPort, proxyUsername, proxyPassword, useActiveProxyAsHttpproxy)

  • settings for the plugin’s up-to-date check and incremental build feature (forceRegenerate, removeOldOutput, produces, cleanPackageDirectories)

maven-javadoc-plugin

Supported versions: 2.7 and above

Supported goals:

  • javadoc:javadoc

  • javadoc:javadoc-no-fork

  • javadoc:test-javadoc

  • javadoc:test-javadoc-no-fork

  • javadoc:jar

  • javadoc:test-jar

Caching is automatically disabled if:

The following properties are deliberately not tracked as inputs, because they should not influence the javadoc output:

maven-checkstyle-plugin

Supported versions: 2.14 and above

Supported goals:

  • check

  • checkstyle

  • checkstyle-aggregate

Caching is automatically disabled if:

The following properties are deliberately not tracked as inputs, because they do not influence the outcome of the goal:

Absolute paths in output files are ignored

Checkstyle’s output files contain absolute paths that are deliberately ignored by the extension. Thus, when loading the goal’s outputs from cache, the referenced paths might not exist on the machine that is executing the build. In case that’s problematic for you, please disable the Build Cache for this goal.

Appendix D: Anatomy of the .gradle-enterprise directory

By default, the Develocity Maven extension stores temporary data in the ${user.home}/.m2/.gradle-enterprise directory. If you want to customize this location, use one of the following options:

Using the Programmatic configuration (Maven extension 1.10.1+)
gradleEnterprise.setStorageDirectory(java.nio.file.Paths.get("/path/to/new/storage/directory"));
$ mvn clean verify -Dgradle.enterprise.storage.directory=path/to/new/storage/directory
Add the following to gradle-enterprise.xml (Maven extension 1.10.3+)
<gradleEnterprise>
  <storageDirectory>/path/to/new/storage/directory</storageDirectory>
</gradleEnterprise>

The directory may contain the following subdirectories:

build-cache

Location of the local Build Cache

build-cache-tmp

Temporary directory for loading and storing entries in the remote Build Cache in case the local Build Cache is disabled

build-scan-data

Data collected to create build scans

fingerprint-cache

Location of the local fingerprint cache

token-cache

Location of cached entitlement tokens

The .gradle-enterprise directory is an internal directory and subject to change without warning.

Appendix E: Release history

1.20.1

8th February 2024
  • [NEW] Add support for the maven-javadoc-plugin version 3.6.3

  • [NEW] Build Cache: Add support for the jaxb-maven-plugin version 4.0.2

  • [FIX] The Maven extension does not ignore .mvn/.gradle-enterprise folder by default when generating a project via init goal

Compatible with scans.gradle.com and Develocity 2023.4 or later.

1.20

5th December 2023
  • [NEW] Build Cache: Add support for mojoExecution property in an upcoming version of maven-javadoc-plugin

  • [NEW] Build Cache: Add support for outputTimestamp property in an upcoming version of maven-compiler-plugin

  • [NEW] Predictive Test Selection: Selection profile can be configured via new pts.profile system property

  • [NEW] Test Distribution/Predictive Test Selection: Add support for develocity-testing-annotations version 2.0

  • [NEW] Test Distribution/Predictive Test Selection: Fall back to regular execution if fallbackToRegularExecutionOnMissingJUnitPlatform POM configuration property or system property is set and JUnit Platform is not available

  • [FIX] Build Scan: Test event capturing fails if TestNG @DataProvider creates arguments with failing toString method in framework versions 6.x

  • [FIX] Build Cache: Develocity Maven extension might store corrupt build cache entries if the clean goal is not executed first

  • [FIX] Test Distribution: Retry filters are not respected if tests are configured to be retried in a new JVM

  • [FIX] Test Distribution/Predictive Test Selection: JUnit’s parallel execution configuration is not respected if a single test executor is used

Compatible with scans.gradle.com and Develocity 2023.4 or later.

1.19.3

17th October 2023
  • [NEW] Predictive Test Selection: Selection profile can be configured via new pts.profile system property

  • [FIX] Build Scan: Test data cannot be captured if TestNG test method is invoked multiple times on different threads

  • [FIX] Build Scan: Intermittent concurrency issue capturing test events in builds using many threads

  • [FIX] Test Distribution/Predictive Test Selection: JUnit’s parallel execution configuration is not respected if a single test executor is used

Compatible with scans.gradle.com and Develocity 2023.3 or later.

1.19.2

5th October 2023
  • [NEW] Build Cache: Add support for maven-javadoc-plugin 3.6.0

  • [NEW] Build Cache: Add support for jaxb-maven-plugin 3.0.0

  • [NEW] Predictive Test Selection: Add pts.enabled system property to enable / disable PTS

Compatible with scans.gradle.com and Develocity 2023.3 or later.

1.19.1

19th September 2023
  • [FIX] Extension is not applied to builds run by IntelliJ IDEA Maven Embedder

  • [FIX] Build Cache: Failsafe test results are cached when JVM terminates

  • [FIX] Build Cache: Failsafe test results are cached when tests are timed out

Compatible with scans.gradle.com and Develocity 2023.3 or later.

1.19

13th September 2023
  • [NEW] Add help goal which provides details on the custom goals of the extension

  • [NEW] Add init goal to ease applying and configuring the extension on a Maven project

  • [NEW] Add support for project level access control

  • [NEW] Build Cache: Add support for legacyMode property in an upcoming version of maven-javadoc-plugin

  • [FIX] Test Distribution: The duration of output file transfers sometimes exceeds the duration of the executor assignment

  • [FIX] Test Distribution: Local executors are sometimes reported as released after the goal has finished

  • [FIX] Test Distribution/Predictive Test Selection: Automatic Java modules trigger execution on module path rather than classpath

Compatible with scans.gradle.com and Develocity 2023.3 or later.

1.18.3

1st February 2024
  • [NEW] Build Cache: Introduce the option to turn off fingerprinting inputs Compatible with scans.gradle.com and Gradle Enterprise 2023.2 or later.

1.18.2

23rd January 2024
  • [NEW] Build Cache: Improve error handling while fingerprinting inputs

Compatible with scans.gradle.com and Gradle Enterprise 2023.2 or later.

1.18.1

27th July 2023
  • [NEW] Test Distribution/Predictive Test Selection: Add support for JUnit 5.10’s new test dry run mode

  • [FIX] Test Distribution: Local test executors are reported as released after test goal has finished

  • [FIX] Test Distribution: Finish event for test execution rarely has older timestamp than its start event

  • [FIX] Test Distribution: Re-scheduled tests are reported after the test executor has been released

Compatible with scans.gradle.com and Develocity 2023.2 or later.

1.18

18th July 2023
  • [NEW] Build Cache: Avoid trying to upload too-large cache entries to built-in and remote Build Cache nodes

  • [NEW] Build Cache: Add support for normalizing system properties

  • [NEW] Build Cache: Add support for annotationProcessorPathsUseDepMgmt property in maven-compiler-plugin

  • [NEW] Build Cache: Add support for additionalClasspathDependencies property in an upcoming version of maven-surefire-plugin

  • [NEW] Test Distribution: Capture configuration and runtime insights in build scans

  • [NEW] Predictive Test Selection: Introduce mode to run remaining tests, i.e. tests that haven’t been executed for the same inputs

  • [NEW] Predictive Test Selection: Introduce selection profiles (conservative/standard/fast) to influence how many tests are selected

  • [FIX] Build Cache: Misconfiguration of goal execution cacheability is not surfaced

  • [FIX] Build Cache: Incorrect display of cacheability reason for system properties

  • [FIX] Build Cache: NullPointerException when output name is not configured

  • [FIX] Test Distribution: JaCoCo coverage output transfer from agents for builds running on Windows

  • [FIX] Predictive Test Selection: Selection requests failing due to sporadic network issues are not retried

Compatible with scans.gradle.com and Develocity 2023.2 or later.

1.17.4

19th June 2023
  • [NEW] Build Cache: Compatibility with the jaxb-maven-plugin version 2.0.2

  • [FIX] Test Distribution/Predictive Test Selection: Test Discovery results with failures are incorrectly cached

  • [FIX] Test Distribution/Predictive Test Selection: Timeout for awaiting response from Develocity is too short when under heavy load

  • [FIX] Predictive Test Selection/Test Retry: Confusing failure message when tests could not be retried

Compatible with scans.gradle.com and Develocity 2023.1 or later.

1.17.3

2nd June 2023
  • [NEW] Build Cache: Add support for excludeGeneratedSources property in an upcoming version of maven-checkstyle-plugin

  • [FIX] Build Scan: Classpath conflict when capturing tests for custom Maven extensions

  • [FIX] Build Scan: Failures when capturing test events when using priorities or running test in parallel for TestNG

  • [FIX] Build Cache: Misleading error message for untracked system properties in surefire goals

  • [FIX] Build Cache: Maven Checkstyle plugin comma-separated includes and excludes are not supported

  • [FIX] Test Distribution/Predictive Test Selection: Configuration failure for Surefire/Failsafe goals on Maven 3.9.3 and later

Compatible with scans.gradle.com and Develocity 2023.1 or later.

1.17.2

9th May 2023
  • [FIX] Build Scan: Test capturing of JUnit 4 Parameterized test classes executed concurrently in the same JVM

Compatible with scans.gradle.com and Develocity 2023.1 or later.

1.17.1

2nd May 2023
  • [FIX] Test Distribution: Build fails for TestNG test classes with @AfterClass methods belonging to different suites

  • [FIX] Test Distribution: Upload of input files with very long names sporadically fails

  • [FIX] Predictive Test Selection: Changed must-run configuration not applied when rerunning test goal

Compatible with scans.gradle.com and Develocity 2023.1 or later.

1.17

12th April 2023
  • [FIX] Test Distribution/Predictive Test Selection: Missing implicit injection of JUnit Jupiter or Vintage engine when missing from test runtime classpath

Compatible with scans.gradle.com and Develocity 2023.1 or later.

1.16.6

28th March 2023
  • [FIX] Build Scan: Dynamically added projects are not captured when discovered during dependency resolution

  • [FIX] Build Scan: javax.net.ssl.* properties are not forwarded to the background upload process

  • [FIX] Build Cache: incorrect server address may yield “Invalid cookie header” warning in build logs

  • [FIX] Test Distribution: classpath conflict with Apache commons-lang and commons-io

Compatible with scans.gradle.com and Develocity 2022.4 or later.

1.16.5

2nd March 2023
  • [FIX] Build Cache: Compile avoidance warning is shown when build cache is disabled

  • [FIX] Test Distribution: Build fails if remote executors are preferred but getting an agent estimation from Develocity times out

Compatible with scans.gradle.com and Develocity 2022.4 or later.

1.16.4

15th February 2023
  • [NEW] Build Cache: Compatibility with the maven-enforcer-plugin version 3.2.1

  • [NEW] Build Cache: Add support for useModulePath property added in maven-compiler-plugin version 3.11.0

Compatible with scans.gradle.com and Develocity 2022.4 or later.

1.16.3

1st February 2023
  • [FIX] Build Scan: Wrong extension application type attribution when passing multiple extensions via the maven.ext.class.path system property

  • [FIX] Build Scan: Develocity server URL is not honoured when using the build-scan-publish-previous goal

  • [FIX] Build Scan: Build fails when applying Maven Build Cache extension

  • [FIX] Build Scan: Build fails for TestNG @Factory test class used in combination with @DataProvider

  • [FIX] Build Scan: Sporadic processing errors of tests retried in a single forked JVM

Compatible with scans.gradle.com and Develocity 2022.4 or later.

1.16.2

5th January 2023
  • [NEW] Build Cache: Automatically track the JaCoCo jacoco-agent.destfile system property as an output

  • [NEW] Build Cache: Automatically mark a goal execution as not cacheable if the JaCoCo jacoco-agent.append system property is present and set to true

  • [NEW] Test Distribution: Do not wait for remote executors when remoteExecutionPreferred=true but no Develocity server is configured

  • [FIX] Test Distribution: Unnecessary connection attempts to Develocity server despite Test Distribution being disabled

Compatible with scans.gradle.com and Develocity 2022.4 or later.

1.16.1

16th December 2022
  • [NEW] Local build caching for Maven no longer requires authorization from the Develocity server

  • [FIX] GradleEnterpriseListener components are not discovered under certain circumstances

  • [FIX] Apache RAT Maven plugin fails the build due to Develocity internal files

Compatible with scans.gradle.com and Develocity 2022.4 or later.

1.16

8th December 2022
  • [NEW] Add built-in support for gradle-enterprise-testing-annotations

  • [NEW] Add automatic discovery of the com.gradle plugin group, for plugin prefix resolutions

  • [NEW] Build Scan: Use reported displayName, e.g. Jupiter’s @DisplayName, instead of the method name as test name for tests run via JUnit Platform or Test Distribution

  • [NEW] Build Scan: Add build-scan-publish-previous goal to publish a Build Scan for the last executed build

  • [NEW] Predictive Test Selection: Persists complete test results in cache

  • [NEW] Predictive Test Selection: Test discovery results are cached locally

  • [FIX] Extensions passed as relative path to the maven.ext.class.path system property are not properly attributed to the MAVEN_EXT_CLASSPATH application type

  • [FIX] Access key defined in Develocity XML configuration is not taken into account for remote build cache authentication

  • [FIX] Predictive Test Selection: Fails with a misleading "internal error" if test task input files could not be determined

Compatible with scans.gradle.com and Develocity 2022.4 or later.

1.15.5

3rd November 2022
  • [NEW] Test Distribution: Retry file upload on content digest mismatch

  • [FIX] Predictive Test Selection: Handling of multiple unique IDs per fully-qualified test class name

Compatible with scans.gradle.com and Develocity 2022.3 or later.

1.15.4

12th October 2022
  • [NEW] Build Scan: Ignore missing file input roots

  • [NEW] Test Distribution: Delete remaining files in temporary workspaces on remote agents in case of failures

  • [NEW] Test Distribution: Use gradle-enterprise-maven-extension/<version> as User-Agent for HTTP requests

  • [NEW] Test Distribution/Predictive Test Selection: Detect and fail for unsupported test engines

  • [FIX] Test Distribution: Concurrency issue causing Surefire/Failsafe goals to fail with CancellationException

  • [FIX] Test Distribution: Log misleading ClassNotFoundException message on Test Distribution agents when stopping worker while session is being opened

  • [FIX] Test Distribution: Write to temporary workspaces after worker on Test Distribution agents was asked to stop

Compatible with scans.gradle.com and Develocity 2022.3 or later.

1.15.3

21st September 2022
  • [FIX] Predictive Test Selection: Remove misleading warning when running with -Dscan without having <publish>ALWAYS</publish> configured

Compatible with scans.gradle.com and Develocity 2022.3 or later.

1.15.2

2nd September 2022
  • [NEW] Build Cache: Add support for showCompilationChanges property in maven-compiler-plugin

  • [NEW] Build Cache: Add support for maven-checkstyle-plugin 3.2.0

Compatible with scans.gradle.com and Develocity 2022.3 or later.

1.15.1

16th August 2022
  • [FIX] Predictive Test Selection: Handle projects non-local root POMs

Compatible with scans.gradle.com and Develocity 2022.3 or later.

1.15

10th August 2022
  • [NEW] Build Scan: Capture the value of storeEnabled goal configuration property

  • [NEW] Build Scan: Capture the location of the Maven home directory

  • [NEW] Build Scan: Capture Maven extensions applied to the build

  • [NEW] Build Cache: Allow configuring inputs and outputs of Maven goals via BuildCacheApi

  • [NEW] Build Cache: Allow configuring runtime classpath normalization via BuildCacheApi

  • [NEW] Build Cache: Allow skipping Maven executions if the given skipIfTrue property is set

  • [NEW] Test Distribution: Added configuration option to restrict the number of partitions for remote session to reduce the impact of disconnects

  • [NEW] Test Distribution: Added option to restrict where a test can be executed (localOnly, remoteOnly)

  • [FIX] Build Scan: Builds with dynamically added projects during build time are supported

  • [FIX] Build Scan: Enhance showing minimum supported plugin version for non cacheable goals for very old plugin versions

  • [FIX] Build Scan: Message is printed when publishIfAuthenticated is set and build does not publish a Build Scan

  • [FIX] Build Scan: Enhance resiliency on errors during ExecutionListener callbacks

  • [FIX] Build Scan: Regenerate malformed workspace IDs

  • [FIX] Build Cache: null Mojo arguments values do not break cacheability

Compatible with scans.gradle.com and Develocity 2022.3 or later.

1.14.4

11th July 2022
  • [NEW] Test Distribution: Added configuration option to restrict the number of partitions for remote session to reduce the impact of disconnects

  • [FIX] Build Scan: Enhance showing minimum supported plugin version for non cacheable goals for very old plugin versions

  • [FIX] Build Scan: Improved warning message when a Build Scancan’t be published

  • [FIX] Build Scan: Builds with dynamically added projects during build time are supported

Compatible with scans.gradle.com and Develocity 2022.2 or later.

1.14.3

23rd June 2022
  • [NEW] Add goal/execution specific storeEnabled flag to not store build cache outputs

  • [FIX] Multiple application of extension via -Dmaven.ext.class.path system property may cause internal errors

  • [FIX] Predictive Test Selection: Test classes with multiple test IDs no longer cause internal errors

Compatible with scans.gradle.com and Develocity 2022.2 or later.

1.14.2

2nd June 2022
  • [NEW] Allow setting more configuration options via system properties (e.g. gradle.enterprise.allowUntrustedServer)

Compatible with scans.gradle.com and Develocity 2022.2 or later.

1.14.1

19th May 2022
  • [NEW] Test Distribution: Add content digest header for uploaded files to ensure integrity

  • [FIX] Build Scan: Disable test capturing when using maven-surefire-plugin/maven-failsafe-plugin versions 2.19 to 2.20.1 due to a bug that was fixed in 2.21.0 and emit a corresponding warning

  • [FIX] Build Scan: Fix capturing of out of bound logs written by goal executions

  • [FIX] Build Scan: Events may be captured out of order under certain circumstances

  • [FIX] Build Scan: Incorrect message is displayed when applying the Develocity Maven extension from several locations

  • [FIX] Test Distribution/Predictive Test Selection: Resolve classpath conflicts when a project has runtime JUnit Platform dependencies

  • [FIX] Predictive Test Selection: Avoid failing test goals with configured include/exclude filters if no tests were selected

  • [FIX] Predictive Test Selection: Fix sporadic inaccuracy of estimated durations of not selected tests by a few milliseconds

Compatible with scans.gradle.com and Develocity 2022.2 or later.

1.14

19th April 2022
  • [NEW] Build Cache: Introduce read-only mode for non-clean builds

  • [NEW] Predictive Test Selection: Add test selection support

  • [FIX] Build Cache: Allow reusing cache entries regardless of the JVM used to run Maven. Previously, the vendor and major version were part of every goal’s cache key. Now, only the major version of the JVM is taken into account for compile and test goals.

Compatible with scans.gradle.com and Develocity 2022.2 or later.

1.13.1

31st March 2022
  • Build Cache: Fix fingerprint cache issue resulting in false-positive cache hits

  • Build Cache: Add support for implicit property in maven-compiler-plugin 3.10.2

  • Test Distribution: Make WebSocket ping interval configurable via internal system property

Compatible with scans.gradle.com and Develocity 2022.1 or later.

1.13

17th March 2022
  • Build Scan: Paths in a Build Scan have the user home directory normalized.

  • Build Scan: Capture whether rerunGoals system property is set.

  • Build Cache: Accessing the remote build cache now follows redirects automatically and enforces usage of HTTPS by default (see Allowing insecure protocols if you need to continue using HTTP).

  • Build Cache: Fingerprints of external dependencies are no longer stored in the Build Cache by default (see Using the Build Cache to store fingerprints of external dependencies for use cases and instructions for re-enabling this behavior).

  • Build Cache: Add support for enablePreview property in maven-compiler-plugin 3.10.1.

Compatible with scans.gradle.com and Develocity 2022.1 or later.

1.12.4

21st February 2022
  • Build Cache: add support for createMissingPackageInfoClass and debugFileName properties in maven-compiler-plugin 3.10.0

Compatible with scans.gradle.com and Develocity 2021.4 or later.

1.12.3

3rd February 2022
  • Build Scan: Properly handle errors within goal fingerprinting

  • Build Cache: Allow configuring useExpectContinue via BuildCacheApi

  • Build Cache: Update Spring from 5.3.12 to 5.3.15 to avoid false reports of CVE-2021-22060 vulnerability

Compatible with scans.gradle.com and Develocity 2021.4 or later.

1.12.2

19th January 2022
  • Build Scan: Fix memory leak when running tests in a forked VM

Compatible with scans.gradle.com and Develocity 2021.4 or later.

1.12.1

12th January 2022
  • Build Scan: Improve error handling around user callbacks

  • Build Scan: Improve SOCKS proxy server support

Compatible with scans.gradle.com and Develocity 2021.4 or later.

1.12

20th December 2021
  • Build Scan: Do not capture information about irrelevant empty directories

  • Build Scan: Capture directory sensitivity and line-ending sensitivity of goal file inputs

  • Build Scan: Protect against uncaught Maven errors

  • Build Cache: Add opt-in support for using HTTP Expect-Continue when uploading entries to the remote Build Cache

  • Test Distribution: Avoid waiting on remote executors when all tests have already been finished

Compatible with scans.gradle.com and Develocity 2021.4 or later.

1.11.1

20th October 2021
  • Fix potential out-of-order Maven events in case of a skipped project, when using Develocity 2021.2.3+

  • Fail hard if Develocity Maven extension is applied via copying the jar in <maven-home>/lib

  • Build Scan: Properly capture OS name and version for macOS 11+

  • Test Distribution: Fix retry behavior for Spock 2 Stepwise test classes

Compatible with scans.gradle.com and Develocity 2021.3 or later.

1.11

15th September 2021
  • Programmatically access the GradleEnterpriseApi with a custom GradleEnterpriseListener implementation

  • Allow configuring access key via GradleEnterpriseApi and gradle-enterprise.xml

  • Fix build/test output capturing when empty byte arrays are written to System.out/System.err

  • Build Scan: Allow opt-out from build and test log capturing

  • Build Scan: Avoid capturing identical tags

  • Build Scan: Fix potential out-of-order event stream with Maven tests

  • Build Scan: Allow capturing links up until 100,000 characters

  • Build Cache: Add support for line ending normalization

  • Test Distribution: Add support for JDK 16 and above without having to specify --add-opens JVM arguments

  • Test Distribution: Validate waitTimeoutInSeconds to be positive

  • Test Distribution: Only warn about unsupported properties if they are configured

  • Test Distribution: Improve error message when forked test JVM terminates unexpectedly

Compatible with scans.gradle.com and Develocity 2021.3 or later.

1.10.5

28th July 2021
  • Build Cache: Prevent incomplete Build Cache entries in rare concurrent build scenarios

  • Build Cache: Improve failure message when Maven is invoked with an invalid configuration

Compatible with scans.gradle.com and Develocity 2021.2 or later.

1.10.4

20th July 2021
  • Test Distribution: Capture logging as test output when logging frameworks are initialized before test execution

Compatible with scans.gradle.com and Develocity 2021.2 or later.

1.10.3

25th June 2021
  • Allow configuring storage directory via gradle-enterprise.xml

  • Allow configuring requireClean via BuildCacheApi

  • Allow disabling the extension via gradle-enterprise.xml, GradleEnterpriseApi, or gradle.enterprise.enabled system property

Compatible with scans.gradle.com and Develocity 2021.2 or later.

1.10.2

11th June 2021
  • Build Scan: Snapshot dependency artifact resolutions of maven-metadata.xml artifacts are properly captured

  • Build Scan: Out of bound test output events are not captured

  • Build Scan: Also use programmatically configured storage directory (introduced in 1.10.1) for temporary files

Compatible with scans.gradle.com and Develocity 2021.2 or later.

1.10.1

8th June 2021
  • Build Scan: Introduce new GradleEnterpriseApi

  • Build Scan: Restore support for custom locales (e.g. tr-TR)

  • Test Distribution: JUnit Platform artifacts on the test runtime classpath/module path take precedence over those included in the extension

  • Test Distribution: Merge JaCoCo coverage data when using a single remote executor along with local executors

Compatible with scans.gradle.com and Develocity 2021.2 or later.

1.10

1st June 2021
  • Build Scan: Capture test output

  • Build Scan: Read user input without requiring the Plexus Interactivity dependency

  • Test Distribution: Support Java Platform Module System (JPMS)

  • Test Distribution: Time out and retry when upgrading a connection to WebSockets hangs

  • Test Distribution: Exclude environment variables configured in the excludedEnvironmentVariables Surefire/Failsafe parameter when forking local test JVMs

  • Test Distribution: Agents are released on agent shutdown once the current partition is finished

Compatible with scans.gradle.com and Develocity 2021.2 or later.

1.9.2

7th May 2021
  • Build Cache: Add support for xrefTestLocation property in maven-checkstyle-plugin 3.2.0

  • Build Cache: Add support for dependencyLinks and addStylesheets properties in maven-javadoc-plugin 3.3.0

  • Test Distribution: Fix cross-OS path mapping to cope with a broader range of inputs

  • Test Distribution: Reuse temporary workspace on test distribution agents across sessions when reuseForks is false

  • Test Distribution/Build Cache: Add support for includeJUnit5Engines and excludeJUnit5Engines property in maven-surefire-plugin and maven-failsafe-plugin 3.0.0-M6

Compatible with scans.gradle.com and Develocity 2021.1 or later.

1.9.1

7th April 2021
  • Build Scan: Reduced memory usage when capturing goal input files

  • Build Scan: Fixed rare case of duplicated dependencies capturing

  • Build Scan: Fixed captured exception messages in some cases

  • Test Distribution: Fixed potentially hanging build when agents disconnect before starting test execution

  • Test Distribution: Compatibility with JDK 16 without having to configure <argLine>

  • Test Distribution: Improved reporting of unrecoverable failures that occurred on Test Distribution agents

  • Test Distribution: Fixed interoperability issue when using Test Distribution agents running on Linux from builds running on Windows

  • Test Distribution: Fixed reporting of output emitted during startup of forked JVMs on Test Distribution agents

  • Test Distribution/Build Scan: Fixed reporting of tests that were in progress when a forked JVM crashed to be listed as "skipped"

Compatible with scans.gradle.com and Develocity 2021.1 or later.

1.9

15th March 2021
  • Build Scan: add Maven dependency resolution capturing

  • Build Scan/Test Distribution: the GRADLE_ENTERPRISE_ACCESS_KEY environment variable allows specifying the access keys for multiple hosts

  • Build Cache: stricter validation of the Develocity pom.xml configuration

  • Test Distribution: improve test scheduling by creating smaller partitions

  • Test Distribution: add support for once-per-JVM setup/teardown behavior via implementations of LauncherSessionListener introduced in JUnit 5.8.0-M1

  • Test Distribution: optimize local execution of single test classes

  • Test Distribution: configuring maxLocalExecutors takes precedence over forkCount

  • Reduced memory usage for builds with lots of input files

Compatible with scans.gradle.com and Develocity 2021.1 or later.

1.8.3

25th February 2021
  • Fix resource leakage when used from IntelliJ IDEA

  • Properly disambiguate parameterized TestNG tests

  • Add support for failOnFlakeCount property in maven-surefire-plugin 3.0.0-M6

Compatible with scans.gradle.com and Develocity 2020.5 or later.

1.8.2

4th February 2021
  • Missing source roots are treated like empty source roots in build scan comparisons

  • Warnings are logged for unsupported Surefire/Failsafe config parameters even when explicitly set to their default value when Test Distribution is enabled

  • Test Distribution output file archives are sanity checked before unpacking to ensure only regular files and directories are created inside the target directory (CVE-2021-26719)

  • Temporary Test Distribution output files are stored in target/test-distribution-outputs instead of directly in test-distribution-outputs in the project’s base directory

Compatible with scans.gradle.com and Develocity 2020.5 or later.

1.8.1

7th January 2021
  • Test goals without test classes no longer fail if Test Distribution is enabled without JUnit Platform test engine on the classpath

  • Potential deadlock when Test Distribution broker connection is lost while tests are being executed is now avoided

  • Output of JVM which discovers / executes tests is printed in case it exits with non-zero exit code

  • Failed attempts to read from or write to the fingerprint cache are now logged as errors but no longer cause the build to fail

  • Fix sporadic ArithmeticException when reconnecting to the Develocity server for Test Distribution

  • File uploads with non-retryable failures now cause test goals to fail instead of making the build hang

  • Fix file path normalization to properly capture file roots (e.g. workspace, local Maven repository)

Compatible with scans.gradle.com and Develocity 2020.5 or later.

1.8

8th December 2020
  • Added support for Test Distribution

  • Build Cache now supports normalization of MANIFEST and properties files

  • Build Cache now ignores empty directories being added or removed to the source tree when calculating cache keys for the maven-compiler-plugin and maven-checkstyle-plugin

  • The <normalization> element in the POM DSL now provides a way to specify that empty directories should be ignored during Build Cache key calculation

  • Tests with failed assumptions in @BeforeAll methods are now captured in build scans correctly

Compatible with scans.gradle.com and Develocity 2020.5 or later.

1.7.2

20th November 2020
  • Track versions of JDK 15 and later correctly as input for code compilation, test execution, and Javadoc generation

  • Fix performance issue caused by querying the machine’s network interfaces for every goal execution

Compatible with scans.gradle.com and Develocity 2020.4 or later.

1.7.1

13th November 2020
  • Fix race condition when using forked test VMs

Compatible with scans.gradle.com and Develocity 2020.4 or later.

1.7

27th October 2020
  • Capture workspace directory project name as top level project name

  • Prevent build exception if using a Maven Surefire/Failsafe plugin < 2.12

  • Properly detect identical tests run by different forked VMs

  • Improve handling of invalid plugin cache configuration in Maven POM DSL

  • Set the content length header when provisioning access keys for improved compatibility with some load balancers

Compatible with scans.gradle.com and Develocity 2020.4 or later.

1.6.8

6th October 2020
  • Correctly handle multiple occurrences of failed dependencies

Compatible with scans.gradle.com and Develocity 2020.3 or later.

1.6.7

22nd September 2020
  • Add support for runOrderRandomSeed property in maven-surefire-plugin and maven-failsafe-plugin 3.0.0-M6

  • Correctly handle multiple executions of the same Maven project

Compatible with scans.gradle.com and Develocity 2020.3 or later.

1.6.6

18th September 2020
  • Properly link logs from sub-processes to the parent goal execution

  • Protect against unexpected failures during project execution

  • Fix error with Maven Build Cache when executing a goal early

Compatible with scans.gradle.com and Develocity 2020.3 or later.

1.6.5

9th September 2020
  • Introduce BuildCacheApi to programmatically configure the Maven Build Cache

Compatible with scans.gradle.com and Develocity 2020.3 or later.

1.6.4

28th August 2020
  • Fix build scans publishing from IntelliJ 2020.2+

Compatible with scans.gradle.com and Develocity 2020.3 or later.

1.6.3

26th August 2020
  • Protect against potentially duplicated Maven SessionStarted execution event callback firing

  • Support obfuscation of identifying data via gradle-enterprise.xml

Compatible with scans.gradle.com and Develocity 2020.3 or later.

1.6.2

11th August 2020
  • Fix test capturing when the JUnit Platform is called from within test code with a modified class loader

Compatible with scans.gradle.com and Develocity 2020.3 or later.

1.6.1

3rd August 2020
  • Fix project structure capturing for sub modules

  • Fix capturing of skipped test classes

  • Fix test capturing when the JUnit Platform is called from within test code

Compatible with scans.gradle.com and Develocity 2020.3 or later.

1.6

27th July 2020
  • Capture if the build scan was uploaded in the background

  • Capture the full project structure when the build is run from a sub-module

  • Do not print test capturing warning for projects with empty test classes directory

  • Fix potential socket stream security vulnerability when capturing tests (CVE-2020-15777)

Compatible with scans.gradle.com and Develocity 2020.3 or later.

1.5.3

22nd June 2020
  • Build caching now supports custom javac executables configured for the maven-compiler-plugin

Compatible with scans.gradle.com and Develocity 2020.2 or later.

1.5.2

5th June 2020
  • Maven Extension XML project XSD is fixed

  • Error when using null values in proxy configuration is fixed

Compatible with scans.gradle.com and Develocity 2020.2 or later.

1.5.1

19th May 2020
  • Credentials for remote Build Cache can be specified via gradle-enterprise.xml

  • Support usage of SpEL expressions in gradle-enterprise.xml

  • Support supply of gradle-enterprise.xml via custom extension jar on the Maven classpath

  • Race condition in Apache Commons Logging class instantiation is mitigated

  • Stale build scan files are cleaned up

Compatible with scans.gradle.com and Develocity 2020.2 or later.

1.5

5th May 2020
  • Uploads build scans in the background after the build has finished

  • Add caching support for Surefire forkNode and jdkToolchain properties

Compatible with scans.gradle.com and Develocity 2020.2 or later.

1.4.1

1st April 2020
  • Fix capturing of unresolvable conflicts in Maven dependency graphs

Compatible with scans.gradle.com and Develocity 2020.1 or later.

1.4

24th March 2020
  • Capture Maven dependencies in build scans

  • Fix test capturing when failure in class-level method happens under special conditions

Compatible with scans.gradle.com and Develocity 2020.1 or later.

1.3.6

30th January 2020
  • Cache configuration declared using the POM DSL takes precedence over built-in configuration

Compatible with scans.gradle.com and Develocity 2019.4 or later.

1.3.5

21st January 2020
  • Extension is deactivated automatically in incompatible IntelliJ IDEA versions

Compatible with scans.gradle.com and Develocity 2019.4 or later.

1.3.4

16th January 2020
  • Add caching support for maven-javadoc-plugin 3.2.0

  • Add caching support for maven-checkstyle-plugin 3.1.1

  • Fix handling of compile source roots when loading outputs of the maven-compiler-plugin from cache

Compatible with scans.gradle.com and Develocity 2019.4 or later.

1.3.3

16th December 2019
  • Build Cache does no longer store broken symbolic links

Compatible with scans.gradle.com and Develocity 2019.4 or later.

1.3.2

13th December 2019
  • Test capturing is disabled when tests are executed with Java < 8

  • Improved help message when authentication is required for build scan publishing

  • Mitigation if slow local host name resolution on macOS

Compatible with scans.gradle.com and Develocity 2019.4 or later.

1.3.1

9th December 2019
  • Users can provide obfuscation functions for captured username, local IP addresses and hostnames

  • String interpolation in Surefire argLine property is supported

Compatible with scans.gradle.com and Develocity 2019.4 or later.

1.3

25th November 2019
  • Add support for authenticated build scans feature

  • Add support for maven-javadoc-plugin 3.2.0

  • Add support for maven-surefire-plugin and maven-failsafe-plugin 3.0.0-M4

  • Logs on debug level are not captured

  • Ignore additional Maven extension applications, when another instance is already applied

Compatible with scans.gradle.com and Develocity 2019.4 or later.

1.2.8

16th October 2019
  • Global gradle-enterprise.xml is now read from ${maven.home}/conf in Maven < 3.5.0

  • Fixed hanging build due to race condition when an error during data capturing occurred

Compatible with scans.gradle.com and Develocity 2019.3 or later.

1.2.7

1st October 2019
  • Extension behaves more lenient towards unusual embeddings of Maven

  • Goal cache key only contains the major Java version

Compatible with scans.gradle.com and Develocity 2019.3 or later.

1.2.6

18th September 2019
  • Reduced runtime and memory allocation overhead of test capturing

Compatible with scans.gradle.com and Develocity 2019.3 or later.

1.2.5

16th September 2019
  • Fixed project structure capturing when a goal is executed very early in the build

  • Fixed test capturing when a custom test provider is specified

Compatible with scans.gradle.com and Develocity 2019.3 or later.

1.2.4

10th September 2019
  • Fixed test capturing when test started event cannot be found

  • Fixed test capturing when duplicate JUnit 4 Descriptions are found

Compatible with scans.gradle.com and Develocity 2019.3 or later.

1.2.3

28th August 2019
  • Add executeOnce Maven build scan API

  • Fixed concurrency issue in test capturing

  • Handle multi-threading and fail-fast scenarios for Maven < 3.6.2

  • Handling of Maven workspace ID is enhanced

Compatible with scans.gradle.com and Gradle Enterprise 2019.3 or later.

1.2.2

23rd August 2019
  • TestNG tests handle orphaned failure events

  • Fixed build hangs when failure occurred during test processing

  • Fixed exceptions in test capturing

Compatible with scans.gradle.com and Gradle Enterprise 2019.3 or later.

1.2.1

20th August 2019
  • Support failing @Before*/@After* annotations in all supported test frameworks

  • Support failing TestNG dependOnMethods and dependsOnGroups tests

  • Don’t fail when null test method name or test class name is encountered

  • Gradle Enterprise server set by configuration is now retrievable from the BuildScanApi

Compatible with scans.gradle.com and Gradle Enterprise 2019.3 or later.

1.2

8th August 2019
  • Capture tests executed in Surefire/Failsafe 2.15+ for JUnit 4/5 and TestNG frameworks

  • Capture console output

  • Add adjacent build scans support for Maven by capturing the workspace ID, unique per project workspace

  • Fixed origin build scan link when there is no reference to the output producing goal

  • Fixed project structure capturing when other extensions/plugins update the internal Maven projects

  • Fixed event serialization error when using custom tags/links/values via the BuildScanApi

  • Enhanced the BuildScanApi:

    • Register a background action

    • Register an action to be done as late as possible before publishing

    • Register an action to be done when a build scan is published

    • Set terms of service params programmatically

    • Set server programmatically

    • Set if untrusted servers are allowed programmatically

    • Specify the publication behaviour programmatically

    • Specify whether goal input files should be captured programmatically

Compatible with scans.gradle.com and Gradle Enterprise 2019.3 or later.

1.1.4

28th June 2019
  • Undeclared inputs are reported correctly on Windows

  • Registering additional inputs/outputs works in the presence of mixed line separators

Compatible with scans.gradle.com and Gradle Enterprise 2019.2 or later.

1.1.3

20th June 2019
  • Add support for upcoming maven-surefire-plugin/maven-failsafe-plugin version 3.0.0-M4

  • Build flags capturing is not based on the MAVEN_CMD_LINE_ARGS environment variable anymore

  • Add support for mojo-executor Maven plugin

  • Failed maven-failsafe tests are no longer cached

Compatible with scans.gradle.com and Gradle Enterprise 2019.2 or later.

1.1.2

17th May 2019
  • Fixed a bug which resulted in wrong event order caused by system clock adjustments

  • Fix handling of ** in include patterns of supported goals and custom input declarations

Compatible with scans.gradle.com and Gradle Enterprise 2019.2 or later.

1.1.1

12th May 2019
  • Read project-specific gradle-enterprise.xml from same .mvn directory that Maven uses to read extensions.xml

Compatible with scans.gradle.com and Gradle Enterprise 2019.2 or later.

1.1

3rd May 2019
  • Output of javadoc:aggregate is cached for maven-javadoc-plugin:2.7+

  • Output of javadoc:aggregate-jar is cached for maven-javadoc-plugin:2.7+

  • Output of javadoc:aggregate-no-fork is cached for maven-javadoc-plugin:2.7+

  • Output of javadoc:test-aggregate is cached for maven-javadoc-plugin:2.7+

  • Output of javadoc:test-aggregate-jar is cached for maven-javadoc-plugin:2.7+

  • Output of javadoc:test-aggregate-no-fork is cached for maven-javadoc-plugin:2.7+

  • Maven log no longer disappears when extension is applied twice

  • Skipped cacheable goals are reported as "skipped" instead of "not cacheable"

  • Local Build Cache issues fail the build instead of logging a warning

  • Extension only snapshots input files that match given include/exclude patterns

  • Fix NullPointerException when trying to resolve a non-existing plugin without version

  • Parallel forked goal executions are captured correctly in build scans

  • Capture finer-grained fingerprint events

Compatible with scans.gradle.com and Gradle Enterprise 2019.2 or later.

1.0.8

18th April 2019
  • Fix handling of null-valued system properties

  • Prevent non existing javadoc jars from being attached

  • java.io.tmpdir is ignored in surefire systemProperties/systemPropertyVariables

Compatible with scans.gradle.com and Gradle Enterprise 2019.1 or later.

1.0.7

17th April 2019
  • Output of javadoc:test-jar is cached for maven-javadoc-plugin:2.7+

  • Output of javadoc:jar is cached for maven-javadoc-plugin:2.7+

  • Output of javadoc:test-javadoc-no-fork is cached for maven-javadoc-plugin:2.7+

  • Output of javadoc:test-javadoc is cached for maven-javadoc-plugin:2.7+

  • Output of javadoc:javadoc-no-fork is cached for maven-javadoc-plugin:2.7+

  • Output of javadoc:javadoc is cached for maven-javadoc-plugin:2.7+

  • Output of generate goal is cached for maven-jaxb2-plugin:0.12.3+

  • Output of checkstyle:check is cached for maven-checkstyle-plugin:2.14+

  • Output of checkstyle:checkstyle is cached for maven-checkstyle-plugin:2.14+

  • Output of checkstyle:checkstyle-aggregate is cached for maven-checkstyle-plugin:2.14+

  • Protect against double applications

  • Protect against event notifications received before initialization (workaround for MNG-6619)

  • Handle more absolute paths in JVM arguments out of the box

  • Broken java executables make goals non-cacheable instead of failing the build

  • System properties now overwrite values in gradle-enterprise.xml

  • Allow same file to appear in multiple output locations (e.g. the summaryFile of the maven-failsafe-plugin)

  • User can add additional inputs and outputs to goal executions using the pom.xml DSL

  • Command line arguments are normalized, removing all known input and output paths from them to allow relocation

  • Caching is deactivated for goals that contain undeclared file paths in their input properties (e.g. JVM args)

Compatible with scans.gradle.com and Gradle Enterprise 2019.1 or later.

1.0.6

26th March 2019
  • Add support for code completion of publishMode in gradle-enterprise.xml

  • Support broken JARs in annotation processor detection

Compatible with scans.gradle.com and Gradle Enterprise 2019.1 or later.

1.0.5

20th March 2019
  • Only fingerprints for external jars are stored in the Build Cache

  • Surefire statistics file and tempDir are tracked as local state

  • Performance improvements for jar fingerprinting and Build Cache load operations

  • More helpful error message for invalid build scan publishing mode configuration

Compatible with scans.gradle.com and Gradle Enterprise 2019.1 or later.

1.0.4

15th March 2019
  • Fix ID generation for Build Cache events

  • Jar fingerprints are stored in the Build Cache

Compatible with scans.gradle.com and Gradle Enterprise 2019.1 or later.

1.0.3

12th March 2019
  • Fix hashing of Build Cache operations, that was leading to event ID collisions

  • Support a proxy server when publishing build scans

  • Prevent publishing build scans when there is no entitlement

Compatible with scans.gradle.com and Gradle Enterprise 2019.1 or later.

1.0.2

6th March 2019
  • Runtime classpath normalization recursively inspects WAR, EAR, ZIP and APK files

  • Track runOrder as input property for the maven-surefire-plugin and maven-failsafe-plugin

  • Fix project capturing to respect <module> declarations

Compatible with scans.gradle.com and Gradle Enterprise 2019.1 or later.

1.0.1

1st March 2019
  • Restore compatibility with Maven < 3.5.2

  • Enhance console output of terms of services

Compatible with scans.gradle.com and Gradle Enterprise 2019.1 or later.

1.0

28th February 2019
  • Initial release

Compatible with scans.gradle.com and Gradle Enterprise 2019.1 or later.

Appendix F: Compatibility with Apache Maven and Develocity

Compatibility between versions of Apache Maven, Develocity, and the Develocity Maven extension can be found here.

Appendix G: Compatibility with Apache Maven plugins

Certain versions of the Apache Maven plugins listed below are incompatible with the Develocity Maven extension. If using one of those plugins, please ensure to use a compatible version.

Plugin Compatible versions Reason

Maven Artifactory Plugin

3.1.0+

Previous versions trigger unexpected Project started/Project finished callbacks

Appendix H: Compatibility with IntelliJ IDEA

No build scans will be published and the Build Cache will not be used when running builds from IDEA versions below 2019.2 or version 2019.3. This is due to issues in these IDEA versions that we can’t work around. We recommend using IDEA 2019.3.1 or above to get the best experience.

Appendix I: Verifying the signature of the extension jar

The extension jar is published to Maven Central alongside its signature (cf. OSSRH Guide). The public key is published to https://keys.openpgp.org. You can verify the signature as follows:

$ curl -OL https://repo1.maven.org/maven2/com/gradle/gradle-enterprise-maven-extension/1.20.1/gradle-enterprise-maven-extension-1.20.1.jar && \
  curl -OL https://repo1.maven.org/maven2/com/gradle/gradle-enterprise-maven-extension/1.20.1/gradle-enterprise-maven-extension-1.20.1.jar.asc && \
  gpg --keyserver keys.openpgp.org --recv-key  7B79ADD11F8A779FE90FD3D0893A028475557671 && \
  gpg --verify gradle-enterprise-maven-extension-1.20.1.jar.asc gradle-enterprise-maven-extension-1.20.1.jar

The output of the last command should look similar to the following:

gpg: Signature made Thu Sep 28 16:17:46 2023 CEST
gpg:                using RSA key 893A028475557671
gpg: Good signature from "Gradle Inc. <info@gradle.com>" [unknown]
gpg:                 aka "Gradle Inc. <maven-publishing@gradle.com>" [unknown]
gpg: WARNING: This key is not certified with a trusted signature!
gpg:          There is no indication that the signature belongs to the owner.
Primary key fingerprint: 7B79 ADD1 1F8A 779F E90F  D3D0 893A 0284 7555 7671

This verifies that the artifact was signed with the private key that corresponds to the imported public key. The warning is emitted because you haven’t explicitly trusted the imported key (hence [unknown]). One way of establishing trust is to verify the fingerprint over a secure channel. Please contact technical support should you wish to do so.

The access key used to sign older versions of Develocity Maven Extension is revoked. Verifying the signature of these prior versions is no longer possible.

Appendix J: Running goals contributed by the Develocity Maven extension

The com.gradle plugin group exposes the gradle-enterprise prefix in Maven Central, which allows to execute goals exposed by the Develocity Maven extension with a shorter syntax.

  • When using Develocity Maven extension version 1.16 or above, the com.gradle plugin group is automatically added to the Maven execution request, so no configuration is needed.

  • When using Develocity Maven extension version < 1.16, you must instruct Maven to search for goal prefixes within the com.gradle plugin group. You must add the following code snippet to your ~/.m2/settings.xml or ${maven.home}/conf/settings.xml.

<pluginGroups>
  <pluginGroup>com.gradle</pluginGroup>
</pluginGroups>

Then, instead of executing

$ mvn com.gradle:gradle-enterprise-maven-extension:<<goal-name>>

you can execute

$ mvn gradle-enterprise:<<goal-name>>

When omitting the Develocity Maven extension version, Maven will select the latest version available. You can force using a given version by executing

$ mvn com.gradle:gradle-enterprise-maven-extension:<<version>>:<<goal-name>>

but this does not work with the goal prefix syntax, unless you declare the extension in your pom.xml.

<build>
  <plugins>
    <plugin>
      <groupId>com.gradle</groupId>
      <artifactId>gradle-enterprise-maven-extension</artifactId>
      <version><<version>></version>
    </plugin>
  </plugins>
</build>
This will execute the goal from the <<version>> extension
$ mvn gradle-enterprise:<<goal-name>>

Goals provided by the Develocity Maven extension

The following goals are exposed by the Develocity Maven extension.

build-scan-publish-previous

(Maven extension 1.16+)

Publishes a Build Scan for the most recently run build.

provision-access-key

(Maven extension 1.3+)

Authenticates your build environment with Develocity.

init

(Maven extension 1.19+)

Sets up the Develocity Maven extension in a Maven project. Without applying the Develocity Maven extension in the first place, you can execute:

mvn com.gradle:gradle-enterprise-maven-extension:1.20.1:init -Dgradle.enterprise.url=https://develocity.mycompany.com

It will:

  • Create/update the .mvn/extensions.xml with the given Develocity Maven extension release version:

  mvn com.gradle:gradle-enterprise-maven-extension:1.20.1:init
  • Create/update the .mvn/extensions.xml with the Develocity Maven extension

  • Create the .mvn/gradle-enterprise.xml pointing to the passed server

  • Create/update .gitignore to ignore .mvn/.gradle-enterprise/

help

(Maven extension 1.19+)

Displays help information on the goals provided by the extension.