Suggestion: Instead of bloating watchexec, you could have your own wrapper that you can use.

Place this in ~/.local/bin/show-exit:

#!/bin/sh

if ("$@"); then
  echo "$(tput setaf 3)Exited successfully$(tput sgr0)"
else
  status=$?
  echo "$(tput setaf 1)Failed with exit code ${status}$(tput sgr0)"
  exit $status
do

Then you can use it in front of any other command.

watchexec -- show-exit make build

I didn't test this script as I'm on my phone right now, but I think it would work.

Partial implementation in 1.18.0:

• no colours
• a message is only printed on non-success return

More improvements are likely!