Comment 37 for bug 2000186

Right, no prompt, that comes from needrestart, and we can't rely on that to restart services for us. The package has to take care of it itself.

I didn't finish the troubleshooting, something else came along, but I think the crux of the problem is that the old prerm script was doing invoke-rc.d stop multipath-tools, and deb-systemd-invoke stop multipath.socket (just the socket). Since we removed the invoke-rc.d part, that left just stopping the socket, which looks like is not really stopping the service. So the new postinst comes along and the "start" that it issues becomes a no-op, because the service was still running.

Maybe we need to add a conditional restart in postinst checking for the package versions, and handle this specific upgrade very specifically.