Things to check before starting a Maven 4.0.0 vote (recommendation) based on "maven-4.0.x" branch .

Discussion thread "[Discussion] What needs to be done for 4.0.0 GA?" on Mailing list

4.0.0-rc-6 milestone tracking

Blocking issues ("bugs")

• issues regarding Build / Consumer parent POMs: see below

Build / Consumer POM

some changes done in RC5 created new blocker issues: https://github.com/apache/maven/issues/11772 (found after JLine released with Maven 4.0.0-RC5 with the new 4.1 model, and other projects started to use the generated consumer POMs from Maven Central)

and tests from public project showed issues:

• with POMs not published to Maven Central: https://github.com/apache/maven/issues/11767

• with profiles https://github.com/apache/maven/issues/11798

Maven 4 API

• Maven API 4 complexity and not final? Do we want to call it "okay as it is" and improve later or do we need/want to get it done before GA?
  • See Elliotte https://lists.apache.org/thread/fp5dnsw93x1v3b43qm2y0nqj6zxbljpn (and other post further on the thread)
  • Similar to this, Maarten's discussion if Maven 4.0.0 is ready to release ("do we feel comfortable to release 4.0.0 in it's current stat) ?"

• Documentation "how to upgrade plugins to Maven 4 API"? SITE-issue 751
• Not a direct blocker for GA release, but I (Gerd, additions on list by Matthias) think Maven (Plugins) should (always) compile/test with the latest 4.x (at least if they are already ported to 4.x). I made some tries on my local machine (macOS). Some components need 4.x, but seem to only work with specific versions:
  Unfortunately, there were API changes between the beta/rcs which require updates of the code.
  Therefore, we should also check if the latest published version of each 4.x component, runs with latest 4.x (independent from the version it needs to build).
• conclusion discussion end of March 2026: https://lists.apache.org/list.html?dev@maven.apache.org, with small summary by Guillaume
  

  On the @Experimental api, I just want to restate what I had in mind :
  * release 4.0 without publicizing the new API
  * finalize 4.x plugins to make them ready for consumption, this could use a few iterations of Maven over the coming months (4.1, 4.2, etc...)
  * when that's done, remove the @Experimental flag and release all plugins in GA
  Basically, ship the API in a "tech preview" mode. We don't make the API public, we don't tell people to migrate their plugins yet...
  But 4.0 brings much more than the API...

• tracking of Maven's Maven 3 plugins build with Maven 4 is the real target for Maven 4.0 (and if possible non-Maven ones, like Mojohaus)
  To check on our own plugins that the Maven 3 compatibility in Maven 4 works at scale, and eventually fix a few edge cases

How to:

1. 1. 1. Git clone source code for all plugins, using maven-sources instructions
      2. build plugins latest SNAPSHOT (with their ITs) with a Maven version (with fail at end to see a global report at the end):
         

         cd aggregator/plugins
         mvn -Prun-its clean verify -fae

         hint: you can also use mvnd to get parallel build

Maven 3 builds on Maven 4 compatibility tests

Maven plugins

=> https://github.com/apache/maven-dist-tool/blob/master/src/site/markdown/plugins-maven4.md created with check-plugins-maven4.sh

Other OSS projects

Guillaume has created an automated test for a looooot of source repositories for many OSS projects if they build on Maven 4: https://github.com/gnodet/maven4-testing/issues
=> tracking progress https://github.com/gnodet/maven4-testing/issues/14270 and followup on 2026-06-02 https://lists.apache.org/thread/211ndr159f5y8wq5kpyn8q3lvfz1nv0h

Maven 4 Namespace

Do we stay with the current state or do we do changes?

• Main discussion (July 2025) with no final decision: https://lists.apache.org/thread/1xmnwgt8q3owsjt8pl2nm4rt5q84zdfc
• Brought up again by Elliotte (February 2026) https://lists.apache.org/thread/fp5dnsw93x1v3b43qm2y0nqj6zxbljpn
• Injected as one aspect of Maarten's discussion if Maven 4.0.0 is ready to release ("do we feel comfortable to release 4.0.0 in it's current stat) ?"
• PRs to document the current state in Maven 3 https://github.com/apache/maven/pull/11809 and Maven 4 https://github.com/apache/maven/pull/11810 (versioned namespace and modelVersion inference, feature added in June 2023 4.0.0-alpha-6)
• PR to change namespace to fixed one from Maven 3 (targets future 4.0.0-rcX, X > 5) https://github.com/apache/maven/pull/10952
• decision?
  • VOTE result = continue using new 4.1.0 namespace

Compatibility of 3rd party tools and infrastructure services

• Ask Jetbrains Team about their opinion on Maven 4.0.0 status
  • Don't see any blockers (Confirmation mail https://lists.apache.org/thread/8kqd92nhno6o4vm1g4l4v78mqqvjmodn )
• Ask Eclipse IDE Team about their opinion on Maven 4.0.0 status
• Ask VS Code Team about their opinion on Maven 4.0.0 status
• Ask Apache Netbeans Team about their opinion on Maven 4.0.0 status
• Reach out to Apache Commons about test status and/or early adoption or opinions
• Reach out to GitHub
• Only fix a specific subset of tasks (*real* blockers with no known workaround)
• Ask Sonatype/Maven Central their opinion on Maven 4.0.0 status
• Reach out to other dependents of the Maven repository system:
  • Bazel
  • Gradle
  • Ivy
  • Bazel

Compatibility of 3rd party "library projects"

• Identify some important stakeholders, projects and power users, maybe JReleaser, Oracle, Eclipse/Apache/IBM/etc. projects etc.

Focus on plugins that have a Maven 4 branch in parallel to the classic Maven 3

not really the focus for Maven 4.0 (which uses Maven 3 plugins), but kept here as a work in progress for future Maven 4.1