[MNG-4595] Unwanted parent plugin execution

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Not A Problem
• Affects Version/s: 2.2.1
• Component/s: Inheritance and Interpolation

Environment

Apache Maven 2.2.1 (r801777; 2009-08-06 21:16:01+0200)
Java version: 1.6.0_18
Java home: C:\Program Files\Java\jdk1.6.0_18\jre
Default locale: en_GB, platform encoding: Cp1252
OS name: "windows xp" version: "5.1" arch: "x86" Family: "windows"

• Assignee: Benjamin Bentmann
• Reporter: Cornel Masson
• Created: 16/Mar/10 12:02
• Updated: 18/Mar/10 05:32
• Resolved: 18/Mar/10 05:32

Description

Searched far and wide but haven't found an answer, so I'm logging this bug.

See attached project zip which demonstrates the problem:

• Project 'util' has 2 assemblies as artifacts:
  • util-config.zip
  • util-unwanted-stuff.zip

• Project 'test-project' depends on 'util's util-config.zip and uses the maven-dependency-plugin to unpack it from the repository

• 'test-project' has project 'root' as parent

• 'root' defines the actual maven-dependency-plugin:unpack executions: one for unpacking util-config.zip (id = unpack-util-config) and another for unpacking util-unwanted-stuff.zip (id = unpack-unwanted-stuff). This is in pluginManagement - and no phase binding is specified in root - so it's inherited by 'test-project', but not automatically executed.

• 'test-project' references the inherited maven-dependency-plugin execution with id unpack-util-config, and binds it to phase package, i.e. only this one assembly should be unpacked:

<plugins>
	<plugin>
		<artifactId>maven-dependency-plugin</artifactId>
		<executions>
			<execution>
				<id>unpack-util-config</id>
				<phase>package</phase>
			</execution>
		</executions>
	</plugin>
</plugins>

However, when you run mvn package on test-project, both assemblies are unpacked. Maven has run both the unpack-util-config and unpack-unwanted-stuff executions of the plugin, as defined in 'root'. It should only have run unpack-util-config, since that is the only one referenced by 'test-project'.

A workaround is to insert a phase binding with a non-existing phase for unpack-unwanted-stuff in 'root', e.g.:

<execution>
	<id>unpack-unwanted-stuff</id>
	<phase>dont-run-this-by-default-stupid-maven</phase>
	<goals>
		<goal>unpack</goal>
	</goals>

If you run mvn package on test-project again, it won't run the unpack-unwanted-stuff with the other one. The fact that this workaround exists makes me wonder if it's related to the "Default Mojo Executions" issue as discussed in http://maven.apache.org/guides/mini/guide-default-execution-ids.html. However, this article claims these issues are fixed as from Maven 2.2.0 onwards (my tests were on 2.2.1).

I've only experienced this problem with the maven-dependency-plugin. I ran a similar test with maven-resources-plugin, but it seems to work correctly, so it might only be related to maven-dependency-plugin. Not 100% sure of this.