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Release Notes – Maven 3.9.2

The Apache Maven team would like to announce the release of Maven 3.9.2.

Maven 3.9.2 is available for download.

Maven is a software project management and comprehension tool. Based on the concept of a project object model (POM), Maven can manage a project's build, reporting, and documentation from a central place.

The core release is independent of plugin releases. Further releases of plugins will be made separately. See the PluginList for more information.

If you have any questions, please consult:

Overview About the Changes

  • Regression fixes from Maven 3.9.1
  • General performance and other fixes

The full list of changes can be found in our issue management system.

Notable New Features

  • Dependency upgrade MNG-7769 lifted Resolver to version 1.9.10. Maven 3.9.1 used Resolver 1.9.7. For changes since Resolver 1.9.7 see release notes for Resolver 1.9.8, 1.9.9 and 1.9.10.
  • Task MNG-7774 implemented interpolation for configuration and command line, but also provides two new properties usable in configuration interpolation: session.topDirectory (reactor top directory) and session.rootDirectory (project root directory, usually where .mvn directory reside). It is recommended to create .mvn directory in project root directory, as presence of this directory is used to detect root directory location. If .mvn directory does not exists, root directory will not be detected, and in such case attempted use of expression session.rootDirectory in interpolation will make Maven refuse to start (will report error). It is important to mention, that those two new properties, are only working within the maven.config file and via the command line. They are NOT usable as configuration properties within your plugin configuration in your pom.xml file.
  • Plugin validation warnings change: they are not littered in console log anymore, but are collected and reported at the build end. Moreover, the validation checks have been extended, more warnings are to be expected if build contains plugins that may not work with upcoming Maven 4. The build end validation report verbosity can be controlled by maven.plugin.validation property values “brief”, “default” and “verbose”. The validation report cannot be turned off, only by not having validation issues in the build, when the report is not shown. See MNG-7712, MNG-7754 and MNG-7767. Almost all of the ASF Maven plugins have been released with fixes to get rid of warnings, updating them is recommended. See Available Plugins page for current plugin versions. For non-ASF plugins, contact plugin maintainers to apply required changes.

Potentially Breaking Core Changes (if migrating from 3.8.x)

  • The Maven Resolver transport has changed from Wagon to “native HTTP”, see Resolver Transport guide.
  • Maven 2.x was auto-injecting an ancient version of plexus-utils dependency into the plugin classpath, and Maven 3.x continued doing this to preserve backward compatibility. Starting with Maven 3.9, it does not happen anymore. This change may lead to plugin breakage. The fix for affected plugin maintainers is to explicitly declare a dependency on plexus-utils. The workaround for affected plugin users is to add this dependency to plugin dependencies until issue is fixed by the affected plugin maintainer. See MNG-6965.
  • Mojos are prevented to boostrap new instance of RepositorySystem (for example by using deprecated ServiceLocator), they should reuse RepositorySystem instance provided by Maven instead. See MNG-7471.
  • Each line in .mvn/maven.config is now interpreted as a single argument. That is, if the file contains multiple arguments, these must now be placed on separate lines, see MNG-7684.
  • System and user properties handling cleanup, see MNG-7556. As a consequence, this may introduce breakage in environments where the user properties were used to set system properties or other way around, for example see MNG-7887.

Known Issues

None.

Complete Release Notes

See complete release notes for all versions