I am new in Maven. Do you know what I am doing wrong (see below)?
mvn -e clean:help.
+ Error stacktraces are turned on.
[INFO] Scanning for projects...
[INFO] Searching repository for plugin with prefix: 'clean'.
[INFO] ------------------------------------------------------------------------
[ERROR] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Required goal not found: clean:help in org.apache.maven.plugins:maven-clean-plugin:2.2
[INFO] ------------------------------------------------------------------------
[INFO] Trace
org.apache.maven.BuildFailureException: Required goal not found: clean:help in org.apache.maven.plugins:maven-clean-plugin:2.2
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.getMojoDescriptor(DefaultLifecycleExecutor.java:1867)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.segmentTaskListByAggregationNeeds(DefaultLifecycleExecutor.java:462)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.execute(DefaultLifecycleExecutor.java:175)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:328)
The version of the plugin you are using on the command line (2.2) does not have the
clean:helpgoal (since 2.3). Try this instead: