I wonder if bash-preexec https://github.com/rcaloras/bash-preexec https://github.com/rcaloras/bash-preexec could be used here. Perhaps you could start a timer

I wonder if bash-preexec https://github.com/rcaloras/bash-preexec https://github.com/rcaloras/bash-preexec could be used here. Perhaps you could start a timer in a preexec, and stop it in precmd. If the elapsed time is greater than some value, notify-send yourself a message that a long-running command has finished.