Plugin Validation

Maven since versions 3.9.x and 4.x introduced Plugin Validation in order to help Maven users and Maven Plugin developers discover issues with the plugins they use or maintain that may break in the future.

These issues are displayed as WARNING either when plugin goal is executed or at the end of the build:

[WARNING] Plugin validation issues were detected in x plugin(s)

and split in two categories based on what actions should be taken:

Internal issues

Internal Plugins Validation issues (project local) are issues discovered in Maven project configuration, like:

  • project using deprecated plugin goals (MNG-7457),
  • project using deprecated plugin parameters,
  • project using read only plugin parameters (MNG-7464).

In such cases, users can fix their project by fixing configuration by editing their POMs. Users should consult actual plugin documentation (and eventually try to update plugin to newer version).

External issues

External Plugins Validation issues (non-configuration) are issues detected in plugin itself, like:

  • plugin using old, deprecated Maven API,
  • plugin declaring dependencies for Maven Core artifacts in wrong scope (should be provided).

External Plugins issues require to be fixed by plugin authors first.

In such cases users can try to update plugin to newer version. If the newest version of plugin still has such an issue, users should report problem to plugin authors.

Manage Plugin Validation verbosity

In order to manage Plugin Validation verbosity, a Maven user property -Dmaven.plugin.validation=... can be used on command line (or injected: see below).

Allowed values are:

  • NONE - mute Plugin Validation completely, nothing will be reported,
  • INLINE (default) - report only Internal issues in place where they occur,
  • BRIEF - report Internal issues in place where they occur and list of plugins with External issues at the end of the build,
  • SUMMARY - report list of plugins with Internal and External issues at the end of the build,
  • VERBOSE - report Internal and External issues at the end of build in verbose mode.

Configuration values for maven.plugin.validation are case insensitive, can only be used on command line (not as property in POM), like:

mvn -Dmaven.plugin.validation=verbose ...

As a consequence:

  • it can be added to MAVEN_OPTS or MAVEN_ARGS environment variables,
  • it can also be added to .mvn/maven.config file in order to configure per project,
  • it can also be added as property in settings.xml file to change configuration globally.

But it can not be used as a POM property in project pom.xml.

Please consult: