Cruise control has the ability to invoke maven multiple times.

This allows you to specify different environment variables for different goals.

This is especially handy when trying to work around issues with maven aggregator
plugins.

To get the project site for a multi-module to work correctly, you often need to
rebuild the root site

$ mvn site
$ mvn -N site
$ mvn site:deploy

Cruise control handles this by separating invocations with a |

I think Hudson can just dynamically add invocations with it's nice UI.

There should be a flag on each invocation that specifies whether this invocation
can fail and not stop subsequent invocations.

i.e. if we have
$ mvn deploy
$ mvn site
$ mvn -N site
$ mvn site:deploy
We might want that
The first failing should result in a failed build.
The second failing should result in an unstable build.
The third failing should not fail the build (maybe mark as unstable).
The fourth failing should result in a failed build.