This is due to Sculptors Eclipse Tycho Maven build has no
Eclipse target platform (providing all the versions / version ranges for the Eclipse OSGi bundles). Without this platform platform (defining fixed versions for all Eclipse plugins / OSGi bundles, e.g. Xtext / Xtend) Sculptors Eclipse Tycho Maven build Tycho happily picks the latest and greatest versions it can find in the configured Eclipse p2 repositories.
In our local build we’re using our own Eclipse p2 mirror. So we’re deciding (by selecting the right time for updating our local mirror) which versions of Eclipse OSGi bundles are present in our local p2 repository.
Travis has no local Eclipse p2 mirror (with a certain set of OSGi bundle versions). Instead it uses the public Eclipse p2 repositories. So if a new version of Eclipse or Xtext / Xtend is released we have to make sure that Sculptor still builds against this new release.
/Torsten