(pasted from message
http://www.nabble.com/Problem-with-incremental-builds-td24799079.html )

We're making use of the new incremental build feature, and I've noticed a problem.

Let's say I have two modules, "library" and "app", with "app" depending on
"library". If a commit fails a unit test in "library", Hudson correctly flags
the build. However, if a subsequent commit occurs on "app" (and "app" only),
Hudson will only execute the build of "app", and despite no one having committed
code to fix the unit test, Hudson reports this subsequent build as "passed".
This is because Hudson only built "app", and did not run library's unit tests.

In my opinion, if a previous build has failed, Hudson should keep using this
build's maven's "pl" argument, appending to it as necessary as more commits are
made. So, in my example, the first build would be invoked "mvn -pl library"
(since that's the module that has changed). The second build would be invoked
"-ol library, app", which is "pl of last build + new changes.