Package: fail2ban Version: 0.10.2-2 Severity: important fail2ban uses 'async' as a parameter/variable name. But it's a reserved keyword in python3.7.
I found the problem in this CI build: https://salsa.debian.org/freedombox-team/plinth/-/jobs/28625 Setting up fail2ban (0.10.2-2) ... File "/usr/lib/python3/dist-packages/fail2ban/client/fail2banclient.py", line 231 def configureServer(self, async=True, phase=None): ^ SyntaxError: invalid syntax File "/usr/lib/python3/dist-packages/fail2ban/client/fail2banserver.py", line 173 async = self._conf.get("async", False) ^ SyntaxError: invalid syntax dpkg: error processing package fail2ban (--configure): installed fail2ban package post-installation script subprocess returned error exit status 1