Is this due to the dropped root privileges of the CUPS daemon? In such a case we must leave CUPS running as root until it sends the signal and drop the privileges afterwards. Or perhaps the caller process needs to drop the root privileges, too (and run as the same user as the daemon) to be able to catch the signal.
-- Cupsys hangs on restart and stop-start https://launchpad.net/bugs/55295 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
