javadoc:javadoc always runs as "aggregator"

If you run the javadoc plugin as report then the @aggregator is ignored (see MNG-2184), I have removed the @aggregator from my local version of the plugin and it passes all its tests but i expect the JavadocJarMojo might suffer (haven't tested yet and i would have too look at the code some more). Personally I cant see why one would want any of the javadoc mojo's functionality to run as an aggregator. Note the 'aggregate' report mojo option is actually implemented inside the mojo, ie. the report exits if it's already been run in the reactor and aggregate is true.

We run the goals "clean javadoc:javadoc install", i.e. we explicitly call the javadoc goal. In the past when running this on a multi-module pom, this triggered the javadoc:javadoc goal on each module. With version 2.3, this triggers the [javadoc:javadoc] as (aggregator-style) on the main pom, and no separate javadoc is generated anymore.

I looked up the bug you linked to but I find it difficult to relate this to this problem. I tried looking up some documentation about @aggregator, but it is not described in the Mojo documentation. I agree with you that the @aggregator seems at odds with the "aggregate" property, but it may be my lack of understanding this feature.

Do you know where I can find more information about how aggregator is supposed to work, and if there are work-arounds to disable aggregator-style?

My observation should have been that when report MOJOs are run from the site plugin they do not honour @aggregator declaration, this is what brett is confirming here. Running the MOJO external to site (i.e. via the command line javadoc:javadoc) appears, according to your experiences, to allow the MOJO to run as an aggregator. I would raise this issue on the @dev list and ask why has this MOJO been made an @aggregator, seems like a mistake to me too. As a workaround either drop back a version or build your own patched version of the plugin?

Got a problem with the aggregator here. Since javadoc 2.3 and the plugin running as an aggregator, our build is broken. Due to the forking of a lifecycle there are arifacts not beeing generated and referenced by other modules. This results in a build failure. Up until now I was unable to create a simple testcase which reproduces our problem. But here is the basic layout of our project.

parent
 +-- assembly
 +-- submodule-A
     +-- mod-A
     +-- mod-B
     +-- mod-C

In our case the mod-B produces a javadoc jar (using javadoc:jar) und creates a assembly using the assembly (attached mojo) plugin. Both mojos are beeing executed at the package phase. The assembly module has a dependecy to the mod-B generated assembly as a zip file. If the javadoc mojo executes and forks the lifecycle, the assembly hasn't been created yet. That means that building assembly is failing due to the missing depenency of mod-B:zip.

Issue which added @aggregator feature

I must confess I still could not figure out how exactly @aggregator affects the plugin's execution, the Mojo API is quite short about this. If there are use-cases that require this annotation, then it might be worth to consider splitting mojos into two: one that has @aggregator and one that has not. This way, the user can choose the appropriate mojo. The Assembly Plugin uses this approach, too.

I'm pretty sure MNG-2184 is to blame here; it seems clear that reporting plugins that use forked lifecycles should not use @aggregator. At least in this case, it seems to be harmful and unnecessary.

FYI, I can't get maven-javadoc-plugin to "mvn install" from trunk (I get test failures), but the 2.3 tag builds just fine; when I remove the @aggregator tag from the mojo, it seems to work perfectly.

http://www.nabble.com/%40aggregator-mojo-annotation-td15302246s177.html

I added an integration test for this in r632888. Unfortunately, I can't figure out how to get it to fail when javadoc plugin's 'jar' goal is run from the pom.

http://svn.apache.org/repos/asf/maven/plugins/trunk/maven-javadoc-plugin/src/it/MJAVADOC-137/

If you check that out and execute 'mvn javadoc:jar' you do not get the javadoc jars. It says:

INFO] [javadoc:jar]
[INFO] Not executing Javadoc as the project is not a Java classpath-capable package

Change pluginManagement to version 2.2 and it will work.

Any idea how to demonstrate that from a pom? I really don't want to touch the code without a failing automated test.

Okay, now in r632911 we have a properly failing test using the invoker plugin. Next step is to revert the changes from MJAVADOC-104.

The changes from MJAVADOC-104 (less some noise) have been reverted [1] and a new snapshot deployed. I'll close this in a few days if there are no further comments.

[1] http://svn.apache.org/viewvc?rev=632945&view=rev