Did this ever happen in focal or later? Did you have apt-cacher installed by chance alongside acng at the time the problem occurred?
** Changed in: apt-cacher-ng (Ubuntu) Status: Confirmed => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1744275 Title: package apt-cacher-ng (not installed) failed to install/upgrade: installed apt-cacher-ng package post-installation script subprocess returned error exit status 1 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/apt-cacher-ng/+bug/1744275/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs