entr lets you watch files and re-run a command any time they change. Whenever I'm working on a script, or go tests, or whatever test-like thing I'm doing that's not in its own bloated test harness, I reach for entr. Great software, does what it's supposed to every time.
I still don't know the root cause, but now I know one more place to look for heisenbugs.
In short, you set up a global hotkey to trigger the rerun of a "key"-ed command. Then you can quickly run a command, which can be rerun with that hotkey.
So, a global hotkey set up for `runrerun -r foo`
Then in a terminal you can use `runrerun -b foo -- <COMMAND>`.
It is a bit over-engineered with multiple sessions, different kill signals for restarts, etc. But that's the gist of it.
Great project tho !
As an example, I use 'guard' [0] in a docker container, and on test failure it writes out to a file which is shared outside the container. It's easy for me to fire up a shell script that uses 'entr' to watch those files and pop up notifications when tests fail.