Gradle Release Notes

Version 5.0-rc-5

The Gradle team is excited to announce Gradle 5.0.

This release features a production-ready Kotlin DSL, dependency version alignment (similar to and usable with Maven BOMs), task timeouts, Java 11 support, and more.

These release notes list what's new since Gradle 4.10. You can review the highlights since Gradle 4.0 here.

Read the Gradle 5.0 upgrade guide to learn about breaking changes and considerations for upgrading from Gradle 4.x.

We would like to thank the following community contributors to this release of Gradle: Jean-Baptiste Nizet, Jonathan Leitschuh, Ben McCann, Björn Kautler, Georg Friedrich, Stefan M., Xiang Li, Theodore Ni, James Justinic, Mike Kobit, Alex Saveau, Kevin Macksamie, Cliffred van Velzen, Artem Zinnatullin, Jakub Strzyżewski, Martin Dünkelmann, Thad House, Dan Sanduleac, Felipe Lima, and thc202.

Table Of Contents

Kotlin DSL 1.0

First and foremost, Gradle Kotlin DSL is now production-ready with it's 1.0 release! Authoring your build logic using Kotlin provides significant additional editing assistance in IDEs, including: improved completion, error highlighting, and refactoring tools. Please read our Gradle Kotlin DSL Primer and follow our migrating build logic from Groovy to Kotlin guide if you're interested. If you prefer the flexibility and dynamic features of Groovy, that's totally okay — the Groovy DSL will not be deprecated.

Kotlin DSL code completion Kotlin DSL error highlighting Kotlin DSL docs Kotlin DSL refactoring

Dependency version alignment

This version of Gradle introduces dependency version alignment. This allows different modules belonging to the same logical group (platform) to have identical versions in a dependency graph. Maven BOMs can be imported to define platforms as well.

dependencies {
    // import a BOM. The versions used in this file will override any other version found in the graph
    implementation(enforcedPlatform("org.springframework.boot:spring-boot-dependencies:1.5.8.RELEASE"))

     // define dependencies without versions
    implementation("com.google.code.gson:gson")
    implementation("dom4j:dom4j")

     // this version will be overriden by the one found in the BOM
    implementation("org.codehaus.groovy:groovy:1.8.6")
}

More details about BOM import can be found in this section of the userguide.

Gradle build initialization features

gradle init functionality has been upgraded in this release: is now optionally interactive, includes new kotlin-library and kotlin-application project types, provides options for configuring project and package names, and more.

interactive gradle init

Interactive mode

If you run the init task from an interactive console, Gradle will prompt you for details of the Gradle build that you'd like to generate.

Kotlin library and applications

The init task can generate a Kotlin library or application, using the kotlin-library or kotlin-application setup type. This was one of our top 10 most voted issues. To try it out, just run gradle init and follow the prompts.

Generated builds use recommended configurations

The init task generates build scripts that use the recommended implementation, testImplementation, and testRuntimeOnly configurations instead of compile, testCompile, and testRuntime, respectively, for all build setup types.

Configure project and source package names

The init task provides a --project-name option to allow you to adjust the name of the generated project, and a --package option to allow you to adjust the package for the generated source. The task will also prompt you to configure these if you run the task interactively.

Create resource directories

The init task creates empty resource directories.

Create a .gitignore file

While the init task does not automatically create a Git repository, the init task generates a simple .gitignore file to make it easier for you to set up a Git repository. This .gitignore file ignores Gradle's build outputs.

Searchable documentation

Search for Gradle Docs is back. The kind folks at Algolia kindly host an index used to allow you to search the user manual and DSL reference.

Docsearch demo

Gradle API Javadocs now take advantage of Javadoc built-in autocomplete, making it easier to find classes and methods you're interested in.

Task timeouts

You can now specify a timeout duration for a task, after which it will be interrupted. Read more about task timeouts in the docs.

HTTP retries during dependency resolution

When Gradle attempts to connect to a remote repository via HTTP, if it fails, Gradle will retry before blacklisting the repository.

No extra configuration is needed. See the section on HTTP retries for more information.

Performance features

Gradle can be started as a low-priority process

You can now use the --priority low command line argument or org.gradle.priority=low property to start Gradle as a low priority process. This ensures that other applications like your IDE or browser stay responsive, even while a very demanding build is running.

Plural task output properties don't disable caching anymore

When using @OutputFiles or @OutputDirectories with an Iterable type, Gradle used to disable caching for the task with the following message:

Declares multiple output files for the single output property 'outputFiles' via @OutputFiles, @OutputDirectories or TaskOutputs.files()

This is no longer the case, and using such properties doesn't prevent the task from being cached. The only remaining reason to disable caching for the task is if the output contains file trees.

JaCoCo plugin now works with the build cache and parallel test execution

The JaCoCo plugin plugin now works seamlessly with the build cache. When applying the plugin with no extra configuration, the test task stays cacheable and parallel test execution can be used.

In order to make the tasks cacheable when generating execution data with append = true, the tasks running with code coverage are configured to delete the execution data just before they starts executing. In this way, stale execution data, which would cause non-repeatable task outputs, is removed.

Since Gradle now takes care of removing the execution data, the JacocoPluginExtension.append property has been deprecated. The JaCoCo agent is always configured with append = true, so it can be used when running tests in parallel.

Java 11 runtime support

Java enthusiasts will be happy to read that this release supports running Gradle builds with JDK 11.

Plugin authoring features

This release introduces useful changes for plugin and custom task authors, including an API for creating SourceDirectorySets, improvements to the Provider API, and improved build cache compatibility.

Public method to create SourceDirectorySet instances

The SourceDirectorySet type is often used by plugins to represent some set of source directories and files. Previously, it was only possible to create instances of SourceDirectorySet using internal Gradle types. This is problematic because when a plugin uses internal types it can often break when new versions of Gradle are released because internal types may change in breaking ways between releases.

In this release of Gradle, the ObjectFactory service, which is part of the public API, now includes a method to create SourceDirectorySet instances. Plugins can use this method instead of the internal types.

Provider implementations track their producer task

An important feature of the Provider API is that Provider instances can track both a value and the task or tasks that produces that value. When a Provider that represents an output of a task is connected to a Property instance that represents a task input, Gradle automatically adds task dependencies between the tasks. This eliminates a class of configuration problems where the location of a task input and the producing task dependencies are not kept in sync as configuration changes are made.

In this release, more Provider implementations track the tasks that produces the value of the provider:

Added Provider.flatMap() method

The flatMap() method allows you to apply a transformation to the values of an existing Provider without realizing the values of that Provider. It returns a new Provider object that is "live" (meaning it will reflect any changes to the values of the original Provider) but will return the transformed values when queried.

Added Property.finalizeValue() method

The property types have a finalizeValue() method which prevents further changes to the value of the property. This is useful in cases where the property needs to be queried and it would be unsafe to then change the value of the property later. After this method as been invoked, calls to methods that change the value of the property (such as set()) will result in an exception.

Task properties are made final before task executes

All task properties that use one of the property types have their value made final when the task executes. This prevents ordering issues where a task property is inadvertently changed after the task executes, resulting in the change having no effect. This will now result in an exception, alerting the user to the unintended error.

Changes to file and directory property construction

ObjectFactory is now used to create file and directory Property instances, similar to other Property types. Previously, this was done using either the methods on DefaultTask, which was available only for DefaultTask subclasses, or using ProjectLayout, only available for projects. Now a single type ObjectFactory can be used to create all property instances in a Gradle model object.

These other methods have been deprecated and will be removed in Gradle 6.0.

Gradle Native features

The Gradle Native project continues to improve and evolve the native ecosystem support for Gradle.

Promoted features are features that were incubating in previous versions of Gradle but are now supported and subject to backwards compatibility. See the User guide section on the “Feature Lifecycle” for more information.

The following are the features that have been promoted in this Gradle release.

Some long existing incubating features have been promoted

The --no-rebuild option is no longer deprecated

A change in buildSrc causes the whole project to become out-of-date. Thus, when making small incremental changes, the --no-rebuild command-line option is often helpful to get faster feedback and is therefore no longer deprecated.

Fixed issues

Known issues

Known issues are problems that were discovered post release that are directly related to changes made in this release.

Reporting of TestNG classes/methods

When using a recent version of TestNG (6.9.13.3 or newer), classes were reported to TestListeners as sibling TestDescriptors of test method TestDescriptors. Now, TestDescriptors of classes are parents of their enclosing method TestDescriptors.

Potential breaking changes

This is a new major version of Gradle, so many of the things that were deprecated in the Gradle 4.x versions have been removed. For examples, there have been fixes to dependency resolution that break corner cases, and running Gradle now requires Java 8 or higher (though tests can be run using Java 6 or 7). Breaking changes are listed with detailed explanations in upgrading Gradle 4.x.

Deprecations

Features that have become superseded or irrelevant due to the natural evolution of Gradle become deprecated, and scheduled to be removed in the next major Gradle version (Gradle 6.0). See the User guide section on the “Feature Lifecycle” for more information.

The following are the newly deprecated items in this Gradle release. If you have concerns about a deprecation, please raise it via the Gradle Forums.

StartParameter properties

The following properties are deprecated and will be removed in Gradle 6.0.

Removing tasks from TaskContainer

Removing tasks from the TaskContainer using the following methods has been deprecated and will be an error in Gradle 6.0.

With the deprecation of every method for removing a task, registering a callback when an object is removed is also deprecated (whenObjectRemoved(Closure/Action)). These methods will be removed in Gradle 6.0

Replacing tasks

It is only safe to replace an unrealized tasks registered with the new Task API because this task has not been used by anything else.

In Gradle 6.0, these behaviors will be treated as errors.

Replacing tasks that may still be used by other tasks

Gradle now emits a deprecation warning when you attempt to replace a task that may have already been used by something else.

Replacing tasks with a task of an incompatible type

Gradle now emits a deprecation warning when you attempt to replace a task with a type that's incompatible from the task being replaced.

Replacing a task that does not exist

Gradle now emits a deprecation warning when you attempt to replace a task that does not already exist.

Removing dependencies from a task

In the next major release (6.0), removing dependencies from a task will become an error.

Gradle will emit a deprecation warning for code such as foo.dependsOn.remove(bar). Removing dependencies in this way is error-prone and relies on the internal implementation details of how different tasks are wired together. At the moment, we are not planning to provide an alternative. In most cases, task dependencies should be expressed via task inputs instead of explicit dependsOn relationships.

Changes to incubating factory methods for creating properties

The following deprecated methods have been removed:

The following methods have been deprecated and will be removed in Gradle 6.0:

Initial value for Property types

The ObjectFactory.property(type), listProperty(type) and setProperty(type) methods no longer set an initial value for the property. Instead, you can use the value() method (or any other mutation method) to set an initial value, if required.

For ListProperty and SetProperty, you can use empty() to initialize the property to an empty collection.

The property append on JacocoTaskExtension has been deprecated

See above for details.

The property effectiveAnnotationProcessorPath on AbstractScalaCompile and JavaCompile has been deprecated

Please use the annotationProcessorPath property on the task's CompileOptions directly.

Deprecated announce plugins

The announce and build announcements plugins have been deprecated.

Deprecated OSGi plugin

The osgi plugin has been deprecated. Builds should migrate to the biz.aQute.bnd plugin.

Deprecated code quality plugins

Resolving configurations in other projects

It is now deprecated behavior to resolve a configuration in another project directly. Projects should interact via project() dependencies declared in configurations of the consuming project. Accessing and resolving configurations in other projects will now produce a deprecation warning.

Resolving configurations from user-managed threads

It is also deprecated behavior to resolve a configuration from a thread that is not managed by Gradle (i.e. a thread created and managed by the user). Threads managed by Gradle (such as the workers that execute tasks) can still resolve configurations safely, but doing so from other threads will now produce a deprecation warning.

External contributions

We would like to thank the following community members for making contributions to this release of Gradle.

We love getting contributions from the Gradle community. For information on contributing, please see gradle.org/contribute.

Upgrade Instructions

Switch your build to use Gradle 5.0 by updating your wrapper properties:

./gradlew wrapper --gradle-version=5.0

Standalone downloads are available at gradle.org/releases.

Reporting Problems

If you find a problem with Gradle 5.0, please file a bug on GitHub Issues adhering to our issue guidelines. If you're not sure you're encountering a bug, please use the forum.

We hope you will build happiness with Gradle 5.0, and we look forward to your feedback via Twitter or on GitHub.