Community
Participate
Working Groups
When you do a project right click and "Maven->Update Project Configuration" the Spring project nature and builder are removed from .project (and others for all I know, but that's the most irritating one). I found an oldish discussion about this which implied that this was fixed, but it still happens for mw with 1.0.100 (STS 2.8.0): http://dev.eclipse.org/mhonarc/lists/m2e-users/msg00733.html. I worked around it by adding the m-e-p configuration as suggested by the OP in the discussion forum, but since that allegedly is *not* supported by m2e, I figure this needs to be looked at again.
I just checked m2e 1.1M3 and it does not remove custom natures and I believe 1.0.x does not do this either. I suspect the behaviour you observe is specific to STS, but we am not able to troubleshoot custom thirdparty eclipse distributions.
Moved to https://github.com/eclipse-m2e/m2e-core/issues/