thanks to firstname.lastname@example.org for reporting this issue
there was a hard to reproduce problem with filenames containing unicode chars in the package marathon-rubicon-data
orbea looked into the problem and sent me this note
I think I figured out why you could not reproduce it. If you build marathon-rubicon-data with 'OPT=yes' can you now reproduce it? I installed sbbdep and marathon-rubicon-data on a clean 14.2 chroot and found I could not reproduce it either. I then rebuilt the marathon-rubicon-data package with 'OPT=yes' to install it in /opt instead of /usr and now I could reproduce the issue again. This makes me wonder why it doesn't have any issues when installed to /usr or why other marathon games do not have the same problem when installed in /opt. I guess the unicode character in the install paths has some problems in this specific case?
needs to be investigated why this is the case