Ok, I got the point. I always built the rpm from a build dir under the source dir.
With your approach, the rpm-package target fails because of the lack of a parent git directory. It expects to retrieve the current version using 'git describe', and it can't because it has no clue on where the sources are.
However I found a solution that leverages the fact that the export archive ships with the version number. This problem is not strictly openSUSE related, but shared across all platforms. It didn't pop up before because the common (suggested) approach is to have a build dir under the sources.
I followed the way I do it on Windows, which I think is the recommended way there :-)
