The CI jobs are failing when ~/.m2/settings.xml are not present
Which hudson do you mean?
The new one from Eclipse?
I don't know several Hudson engines Christian so indeed the legacy one.
Yeah of course there are different engines. 1.x, 2.x and the new 3.x. There is a fast lifecycle, because Hudson is now an Eclipse project (http://www.infoworld.com/d/application-development/oracle-hands-hudson-eclipse-jenkins-fork-seems-permanent-021).
I will be glad if the support isn't stopped for Hudson 3.x.
Hudson and Jenkins code base have diverged, supporting both of them in a single plugin costs too much. We'll see if the community wants to take over Hudson support, but for now, we won't put effort in it.
Mainly it is now maintained from the Hudson developers, which always ports the new version if they have time.