I am getting similar behaviour, also where the antrun and xdoclet plugins are deployed side by side.
The error is slightly different, the full exception is listed below.
The workaround of defining v1.0 for the antrun plugin doesn't work in this case.
At the moment, xdoclet-maven-plugin is dead in the water on maven v2.0.6.
[INFO] ------------------------------------------------------------------------
[ERROR] BUILD ERROR
[INFO] ------------------------------------------------------------------------
[INFO] Internal error in the plugin manager executing goal 'org.codehaus.mojo:xd
oclet-maven-plugin:1.0-alpha-2:xdoclet': Unable to find the mojo 'org.codehaus.m
ojo:xdoclet-maven-plugin:1.0-alpha-2:xdoclet' in the plugin 'org.codehaus.mojo:x
doclet-maven-plugin'
org/apache/tools/ant/PropertyHelper
[INFO] ------------------------------------------------------------------------
[INFO] Trace
org.apache.maven.lifecycle.LifecycleExecutionException: Internal error in the pl
ugin manager executing goal 'org.codehaus.mojo:xdoclet-maven-plugin:1.0-alpha-2:
xdoclet': Unable to find the mojo 'org.codehaus.mojo:xdoclet-maven-plugin:1.0-al
pha-2:xdoclet' in the plugin 'org.codehaus.mojo:xdoclet-maven-plugin'
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoals(Defa
ultLifecycleExecutor.java:543)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoalWithLi
fecycle(DefaultLifecycleExecutor.java:480)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoal(Defau
ltLifecycleExecutor.java:459)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoalAndHan
dleFailures(DefaultLifecycleExecutor.java:311)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeTaskSegmen
ts(DefaultLifecycleExecutor.java:278)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.execute(DefaultLi
fecycleExecutor.java:143)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:334)
at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:125)
at org.apache.maven.cli.MavenCli.main(MavenCli.java:272)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.
java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAcces
sorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.codehaus.classworlds.Launcher.launchEnhanced(Launcher.java:315)
at org.codehaus.classworlds.Launcher.launch(Launcher.java:255)
at org.codehaus.classworlds.Launcher.mainWithExitCode(Launcher.java:430)
at org.codehaus.classworlds.Launcher.main(Launcher.java:375)
Caused by: org.apache.maven.plugin.PluginManagerException: Unable to find the mo
jo 'org.codehaus.mojo:xdoclet-maven-plugin:1.0-alpha-2:xdoclet' in the plugin 'o
rg.codehaus.mojo:xdoclet-maven-plugin'
at org.apache.maven.plugin.DefaultPluginManager.getConfiguredMojo(Defaul
tPluginManager.java:571)
at org.apache.maven.plugin.DefaultPluginManager.executeMojo(DefaultPlugi
nManager.java:421)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoals(Defa
ultLifecycleExecutor.java:539)
... 16 more
Caused by: org.codehaus.plexus.component.repository.exception.ComponentLookupExc
eption: Unable to lookup component 'org.apache.maven.plugin.Mojoorg.codehaus.moj
o:xdoclet-maven-plugin:1.0-alpha-2:xdoclet', it could not be created
at org.codehaus.plexus.DefaultPlexusContainer.lookup(DefaultPlexusContai
ner.java:335)
at org.codehaus.plexus.DefaultPlexusContainer.lookup(DefaultPlexusContai
ner.java:440)
at org.apache.maven.plugin.DefaultPluginManager.getConfiguredMojo(Defaul
tPluginManager.java:562)
... 18 more
Caused by: org.codehaus.plexus.component.factory.ComponentInstantiationException
: Could not instanciate component: role: 'null', implementation: 'org.codehaus.m
ojo.xdoclet.XDocletMojo'
at org.codehaus.plexus.component.factory.java.JavaComponentFactory.makeE
xception(JavaComponentFactory.java:77)
at org.codehaus.plexus.component.factory.java.JavaComponentFactory.newIn
stance(JavaComponentFactory.java:62)
at org.codehaus.plexus.DefaultPlexusContainer.createComponentInstance(De
faultPlexusContainer.java:1464)
at org.codehaus.plexus.component.manager.AbstractComponentManager.create
ComponentInstance(AbstractComponentManager.java:93)
at org.codehaus.plexus.component.manager.PerLookupComponentManager.getCo
mponent(PerLookupComponentManager.java:48)
at org.codehaus.plexus.DefaultPlexusContainer.lookup(DefaultPlexusContai
ner.java:331)
... 20 more
Caused by: java.lang.NoClassDefFoundError: org/apache/tools/ant/PropertyHelper
at java.lang.Class.getDeclaredConstructors0(Native Method)
at java.lang.Class.privateGetDeclaredConstructors(Class.java:2357)
at java.lang.Class.getConstructor0(Class.java:2671)
at java.lang.Class.newInstance0(Class.java:321)
at java.lang.Class.newInstance(Class.java:303)
at org.codehaus.plexus.component.factory.java.JavaComponentFactory.newIn
stance(JavaComponentFactory.java:44)
... 24 more
I am getting similar behaviour, also where the antrun and xdoclet plugins are deployed side by side.
The error is slightly different, the full exception is listed below.
The workaround of defining v1.0 for the antrun plugin doesn't work in this case.
At the moment, xdoclet-maven-plugin is dead in the water on maven v2.0.6.
[INFO] ------------------------------------------------------------------------
[ERROR] BUILD ERROR
[INFO] ------------------------------------------------------------------------
[INFO] Internal error in the plugin manager executing goal 'org.codehaus.mojo:xd
oclet-maven-plugin:1.0-alpha-2:xdoclet': Unable to find the mojo 'org.codehaus.m
ojo:xdoclet-maven-plugin:1.0-alpha-2:xdoclet' in the plugin 'org.codehaus.mojo:x
doclet-maven-plugin'
org/apache/tools/ant/PropertyHelper
[INFO] ------------------------------------------------------------------------
[INFO] Trace
org.apache.maven.lifecycle.LifecycleExecutionException: Internal error in the pl
ugin manager executing goal 'org.codehaus.mojo:xdoclet-maven-plugin:1.0-alpha-2:
xdoclet': Unable to find the mojo 'org.codehaus.mojo:xdoclet-maven-plugin:1.0-al
pha-2:xdoclet' in the plugin 'org.codehaus.mojo:xdoclet-maven-plugin'
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoals(Defa
ultLifecycleExecutor.java:543)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoalWithLi
fecycle(DefaultLifecycleExecutor.java:480)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoal(Defau
ltLifecycleExecutor.java:459)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoalAndHan
dleFailures(DefaultLifecycleExecutor.java:311)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeTaskSegmen
ts(DefaultLifecycleExecutor.java:278)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.execute(DefaultLi
fecycleExecutor.java:143)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:334)
at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:125)
at org.apache.maven.cli.MavenCli.main(MavenCli.java:272)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.
java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAcces
sorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.codehaus.classworlds.Launcher.launchEnhanced(Launcher.java:315)
at org.codehaus.classworlds.Launcher.launch(Launcher.java:255)
at org.codehaus.classworlds.Launcher.mainWithExitCode(Launcher.java:430)
at org.codehaus.classworlds.Launcher.main(Launcher.java:375)
Caused by: org.apache.maven.plugin.PluginManagerException: Unable to find the mo
jo 'org.codehaus.mojo:xdoclet-maven-plugin:1.0-alpha-2:xdoclet' in the plugin 'o
rg.codehaus.mojo:xdoclet-maven-plugin'
at org.apache.maven.plugin.DefaultPluginManager.getConfiguredMojo(Defaul
tPluginManager.java:571)
at org.apache.maven.plugin.DefaultPluginManager.executeMojo(DefaultPlugi
nManager.java:421)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoals(Defa
ultLifecycleExecutor.java:539)
... 16 more
Caused by: org.codehaus.plexus.component.repository.exception.ComponentLookupExc
eption: Unable to lookup component 'org.apache.maven.plugin.Mojoorg.codehaus.moj
o:xdoclet-maven-plugin:1.0-alpha-2:xdoclet', it could not be created
at org.codehaus.plexus.DefaultPlexusContainer.lookup(DefaultPlexusContai
ner.java:335)
at org.codehaus.plexus.DefaultPlexusContainer.lookup(DefaultPlexusContai
ner.java:440)
at org.apache.maven.plugin.DefaultPluginManager.getConfiguredMojo(Defaul
tPluginManager.java:562)
... 18 more
Caused by: org.codehaus.plexus.component.factory.ComponentInstantiationException
: Could not instanciate component: role: 'null', implementation: 'org.codehaus.m
ojo.xdoclet.XDocletMojo'
at org.codehaus.plexus.component.factory.java.JavaComponentFactory.makeE
xception(JavaComponentFactory.java:77)
at org.codehaus.plexus.component.factory.java.JavaComponentFactory.newIn
stance(JavaComponentFactory.java:62)
at org.codehaus.plexus.DefaultPlexusContainer.createComponentInstance(De
faultPlexusContainer.java:1464)
at org.codehaus.plexus.component.manager.AbstractComponentManager.create
ComponentInstance(AbstractComponentManager.java:93)
at org.codehaus.plexus.component.manager.PerLookupComponentManager.getCo
mponent(PerLookupComponentManager.java:48)
at org.codehaus.plexus.DefaultPlexusContainer.lookup(DefaultPlexusContai
ner.java:331)
... 20 more
Caused by: java.lang.NoClassDefFoundError: org/apache/tools/ant/PropertyHelper
at java.lang.Class.getDeclaredConstructors0(Native Method)
at java.lang.Class.privateGetDeclaredConstructors(Class.java:2357)
at java.lang.Class.getConstructor0(Class.java:2671)
at java.lang.Class.newInstance0(Class.java:321)
at java.lang.Class.newInstance(Class.java:303)
at org.codehaus.plexus.component.factory.java.JavaComponentFactory.newIn
stance(JavaComponentFactory.java:44)
... 24 more