I finally created an ad-hoc reporting script to track Maven 4 compatibility on Maven's Maven 3 plugins: https://github.com/apache/maven-dist-tool/blob/master/src/site/markdown/plugins-maven4.md
we already have 2 PRs ready to merge to fix some small incompatibilities and a few other cases to dive into for people interested in getting Maven 4.0.0-rc6 released then GA, please help https://github.com/apache/maven/milestone/127 Regards, Hervé On 2026/03/27 14:39:03 Hervé Boutemy wrote: > re-publishing to the expected thread: > > no feedback: does it mean everybody is surprised? agrees/disagrees? > > I worked on establishing the status of ASF Maven plugins: > https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=406620656#Maven4.0.0GAchecklist-Maven4API > > I all starts by establishing if existing Maven 3 plugins work with Maven 4 or > not: I did it for plugins that went to a Maven 4-specific branch > > I think doing that check on ALL ASF Maven plugins would make sense, to > establish how our "Maven 3 plugins compatibility plan" works or not > > and when a plugin fails initially, establishing why, and if a fix can be done > without creating the Maven 4 branch, would be useful > > Help welcome > > Hervé > > > On 2026/03/22 03:22:14 Hervé Boutemy wrote: > > extracting that topic, for clarity > > > > my personal opinion on "It should be clear and documented why the new API > > is > > there, what it looks like / how it is used and how to upgrade to it." > > > > what has to be clear is that: > > 1. Most Maven 3.x plugins should work out of the box > > 2. Plugins using Maven 2.x APIs will break > > 3. Extensions are likely to need updates > > 4. Maven 4 API Architecture: Currently flagged as experimental > > > > I just extracted from slides 14 and 15 of the great slick slides: > > https://gnodet.github.io/maven4-presentation/ > > > > > > I'll add my own words: > > 5. do not upgrade your Maven 3 plugins to Maven 4 API unless you get a real > > benefit of that effort, as you'll have to maintain 2 branches in parallel > > 6. but test and prepare: this experimental phase is useful to check how the > > API is complete enough > > > > We can also explain what we did at Apache Maven: > > - created a few Maven 4-specific plugins to benefit from new features (for > > example Maven Compiler Plugin multi-Java module) > > - created a test "mvn4" branch for our 50 plugins for checking: not really > > maintained, no backport of main branch updates, but a test > > > > I'd love us to clearly document why we did a few Maven 4 plugins before > > Maven > > 4.0.0 GA: I had to dive into Java Module support to understand the Maven > > Compiler Plugin case > > I'd love to get help to create a clear list of which plugins we did and why. > > BTW this will be useful for users: "Maven 4 plugin because Maven 3 plugin > > does > > not work in Maven 4" is different from "Maven 4 plugin to benefit form some > > Maven 4 specific features"). > > > > and yes, this will also let us time to write some examples, return of > > experience, more doc > > > > we need to remain simple and reasonable: Maven 3 plugins remain first class > > citizens in Maven 4 > > It's only when Maven 4 will rise that really publishing Maven 4 (specific) > > plugins will make sense: it will take years > > > > This is the only viable way of going forward: > > - we are not a company with resources to migrate and double maintain our > > own > > 50 plugins > > - we will not drop our Maven 3 plugins for a good number of years > > - there are 7.500 community plugins in Maven Central [1]: Maven 3 > > compatibility in Maven 4 is the default path for a long time > > - the friction of people discovering that their plugins that work in Maven > > 3 > > are in fact Maven 2 plugins that were working in Maven 3 "compat mode" will > > be > > a first complexity > > > > notice: I don't remember fully what Tamasz had in mind for Maven 3.10 > > scope, > > but a clear WARNING "Maven 2 plugin detected: will break soon" would be > > useful > > (perhaps it exists, but we don't promote it sufficiently yet) > > > > > > We need to answer 2 questions for getting Maven 4.0.0 GA with this API > > topic > > covered: > > 1. Is it clear? > > 2. Do we agree? Or is there another proposal? > > > > Regards, > > > > Hervé > > > > > > [1] https://central.sonatype.com/search?q=p%3Amaven-plugin > > > > Le dimanche 22 février 2026, 12:09:38 CET Matthias Bünger a écrit : > > > Hi all, > > > I personally only care about the state of Maven API for plugin > > > maintainers (including the Maven team). It should be clear and > > > documented why the new API is ther, what it looks like / how it is used > > > and how to upgrade to it. As mentioned several times and also added by > > > Gerd to the "open To Dos for 4.0.0 list" not even our plugins are in > > > line with the API and there a breaking changes between literally every > > > beta/rc version. I offered several times to write documentation about > > > this if someone tells me what I have to write, because I have no clue > > > about the plugin API (neither for Maven 3 or 4). > > > > > > I don't care about namespace changes in the build.pom. The consumer POM > > > is unchanged so it is the same since Maven 2 and the ecosystem can work > > > with it. > > > > > > I see the possibilty that we have to do bigger changes before we are > > > fine for a Maven 4. And maybe we need to be brave / honest enough to go > > > back from RC phase to beta if this is required - even if it might raise > > > the "danger" of lurkers coming out of the dark to restart discussion to > > > add other things, like Java 21 or merge current 4.1. into 4.0 together > > > to have mixings from the 4.0.0 start. > > > > > > Other topic: I know that there is nothing like "benevolent dictator" in > > > ASF project, but I have the feeling that we need something like this to > > > somehow end discussions and be it only to decide to start a binding vote. > > > > > > Matthias > > > > > > > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: [email protected] > > For additional commands, e-mail: [email protected] > > > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [email protected] > For additional commands, e-mail: [email protected] > > --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
