Please attach sample project that would allow us to reproduce this issue. Thanks.

I checked out the latest version from svn and it works.

BTW: When i enable the Include Modules feature from the maven container, the class Maven2Builder gets a NPE in line 103.

We still going to need a test project to reproduce that.

1. install the plugin
2. refresh eclipse
3. insert a space in the demo pom and save
4. the error message appears in the demo pom

Thomas, thanks fro the test case. I've been able to reproduce this issue. In 0.0.11 release you'll see error like
"The PluginDescriptor for the plugin org.maven.ide.eclipse.projects:MNGECLIPSE-380-plugin was not found MNGECLIPSE-380-demo". It seems like a problem with our workspace project resolution and the only workaround for now is to close plugin project, so workspace resolver won't see it. Also note that you don't need to edit pom.xml to rebuild classpath container, just kick Project / Clean... action.

Jason, it looks like our custom resolver don't update some info in the pluginCollector instance. See stack trace below. Can you please tell me what can we do about this?

java.lang.IllegalStateException: The PluginDescriptor for the plugin org.maven.ide.eclipse.projects:MNGECLIPSE-380-plugin was not found
at org.apache.maven.plugin.DefaultPluginManager.addPlugin(DefaultPluginManager.java:415)
at org.apache.maven.plugin.DefaultPluginManager.addPlugin(DefaultPluginManager.java:325)
at org.apache.maven.plugin.DefaultPluginManager.verifyVersionedPlugin(DefaultPluginManager.java:229)
at org.apache.maven.plugin.DefaultPluginManager.verifyVersionedPlugin(DefaultPluginManager.java:193)
at org.apache.maven.plugin.DefaultPluginManager.verifyPlugin(DefaultPluginManager.java:182)
at org.apache.maven.embedder.MavenEmbedder.verifyPlugin(MavenEmbedder.java:351)
at org.apache.maven.embedder.MavenEmbedder.findArtifactTypeHandlers(MavenEmbedder.java:388)
at org.apache.maven.embedder.MavenEmbedder.readProjectWithDependencies(MavenEmbedder.java:446)
at org.maven.ide.eclipse.embedder.MavenModelManager.readMavenProject(MavenModelManager.java:377)
at org.maven.ide.eclipse.embedder.BuildPathManager.resolveClasspathEntries(BuildPathManager.java:232)
at org.maven.ide.eclipse.embedder.BuildPathManager.updateClasspathContainer(BuildPathManager.java:193)
at org.maven.ide.eclipse.container.Maven2Builder.build(Maven2Builder.java:92)
at org.eclipse.core.internal.events.BuildManager$2.run(BuildManager.java:624)
...

This bug occur with flex mojo plugin too, when we set :
<plugin>
<groupId>info.rvin.mojo</groupId>
<artifactId>flex-compiler-mojo</artifactId>
<extensions>true</extensions>
</plugin>

Without extensions, there is non errors

Hi,

You can find a sample of failing POM bellow :
http://code.google.com/p/igenko/source/browse/trunk/igenko-backoffice-server/pom.xml

I have a message : fail to resolve extension plugin.

Sébastien, I really don't want us to guess what you have been doing. Can you please provide step by step instructions and specify when exactly you have that fail message. It would be much easier for use to work with small self-contained test project then trying to extract relevant pieces and resolve missing artifacts in your real projects. Thanks.

To clarify, m2eclipse does not resolve maven plugins from Eclipse workspace. Because extension plugins are essential for maven projects, maven fails processing pom.xml if it cannot resolve any of the extension plugins. Current workaround is to install the plugin into your local maven repository.

Please find attached a test cased where m2eclipse trigger an error.

If you remove <extensions>true</extensions> from pom.xml, there is no more error but the plugin no more works

Sébastien, please note that this issue is only about Maven plugins that code is in Eclipse Workspace. Currently those excplicitly disabled for resolving from Workspace and they always resolved from local or remote Maven repositories (hence plugins need to be deployed there).

So, the project you've attached is showing a completely unrelated issue. Please open separate jira issue for this. Note that root cause there is related to embedded Maven can't download flex-compiler-mojo from any repository. If you run maven build from the command line and then close and reopen your project in Eclipse, it will work. Also note that you need to specify both <repository> and <pluginRepository>.

Workspace resolution of extensions plugins should work now.