See https://copr.fedorainfracloud.org/coprs/g/python/python3.8/package/python-marrow-mailer/ for actual logs. This report is automated and not very verbose, but feel free to ping me for help.
The problem is in python-marrow-util package which is archived upstream so I'm gonna retire both of them. See https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/thread/X6YYLZ3UREJTH776S4EWSKCAXWIZYEOH/
Package has been retired in Fedora rawhide.
I've removed python-marrow-util and python-marrow-mailer from the Python 3.8 copr.