[turborepo] early exit when trying to use rollup's watch mode

[NullVoxPopuli]

What version of Turborepo are you using?

1.9.6

What package manager are you using / does the bug impact?

pnpm

What operating system are you using?

Mac

Describe the Bug

rollup's watch mode is killed by turbo, or not waited for?, hard to tell.

Expected Behavior

turbo does not early exit, and rollup continues building / watching for changes.

To Reproduce

Also written here: NullVoxPopuli/limber#926

1. git clone git@github.com:NullVoxPopuli/limber.git
2. cd limber
3. git checkout how-to-get-turbo-rollup-watching
4. pnpm i --ignore-scripts
5. observe that in packages/ember-repl/addon/package.json the start script is rollup --config --watch
6. try to start watch mode via turbo: pnpm turbo start --filter ember-repl
7. observe that turbo exited, when it should have not-exited due to rollup being in watch mode
8. cd packages/ember-repl/addon
9. pnpm start
10. observe that the start script in this package is a long-running watch mode that doesn't exit unless Ctrl+C is pressed (or some other kill/stop process signal is sent to the process)

Reproduction Repo

NullVoxPopuli/limber#926

[nathanhammond]

Hey @NullVoxPopuli! As a first pass I looked at the turbo.json and your command (filtered) and it seems not likely to be the case, but: is it possible that you have another task in the execution which is exiting non-zero? Unless you specify --continue turbo will bail at the exact moment any task exits non-zero.

Dropping this as a "just in case" bit of feedback, will take a more-detailed pass later.

[NullVoxPopuli]

Hello! Thanks for looking in to this!

it possible that you have another task in the execution which is exiting non-zero?

I don't think so -- in the reproduction, there are no other tasks?

[mehulkar]

I can reproduce this in a much simpler example too: https://github.com/mehulkar/turbo-issue-4983. Need to look into how the rollup executable works. I tried passing --no-stdin to rollup just in case I'd get lucky with that explanation, but that didn't work.

[mehulkar]

Ok , this seems somewhat related to rollup/rollup#5004 and related issues pointed there. I tried rollup@3.20 in the example and it seems to work. I've updated the readme in the instructions to show how it working with the older version.