Hi Ralf:

I am not sure how things work in travis ci 8-(. I have been looking into how
to log into a test container to debug the xfail cache issue that you may have fixed with
changeset:   6651:da6c9050a79e.

Does /nobackup/ralf/share/locale exist? If so this might be breakage from
roundup trying to find the prefix and appending share/local at line 70
in i18n.py. This code is fragile and I am not happy with it but it's an attempt
to find the locale directory where setup placed the locale files.
 
I pushed both your changes to ci. We shall see how they do.