should be able to control restart behaviour when --before-startup-shell command returns nonzero

[mwotton]

Describe the feature you’d like to be implemented

I'm using the --before-startup-shell hpack technique, but if i fumble the package.yaml edit, the whole ghciwatch process dies. ideally it'd just wait for another edit to trigger a reload.

List alternatives to the feature and their pros and cons

I could do something like hpack; true as the argument, but then it'd load the ghci session using the old cabal file and I wouldn't necessarily notice the problem.

Additional context

It's annoying to have to keep restarting the process when I fumble an edit.

[mwotton]

no, i've misunderstood the problem I think. hpack successfully runs and creates a bad cabal file, so it's dying later.