Today was investigating the warnings around some of my eclipse maven projects and noticed that I have a few

There are no JREs installed in the workspace that are strictly compatible with this environment

messages. It took some time to figure out that it was actually the maven-compiler-plugin causing the the J2SE version to be picked up correctly. If I changed the packaging of the maven project to jar everything was generated fine. After some searching it turned out there is a bug with the generation tool m2eclipse I use. As described here the bug was fixed TODAY by removing the java nature from the project, which in turn removes the .classpath necessity which in turns removes the warnings. Few errors less – great work m2eclipse :).