It seems that the rawhide s390x builders hang in various different places, randomly:
https://koji.fedoraproject.org/koji/getfile?taskID=20584916&volume=DEFAU... (stuck at wcsmbs)
https://koji.fedoraproject.org/koji/getfile?taskID=20592419&volume=DEFAU... (stuck at symlink.list)
https://koji.fedoraproject.org/koji/getfile?taskID=20592419&volume=DEFAU... (stuck at PluginFrame_test)
https://koji.fedoraproject.org/koji/taskinfo?taskID=20583725 (stuck who knows where)
I don't know if this is an issue with the mainframe, its storage, or the Fedora kernel running on those builders (4.10.8-200.fc25.s390x according to the glibc build log). Considering the wide variety of affected packages and the randomness of the failure, I don't think it's a packaging problem.
Thanks, Florian