Pretty-print error output if a command failed in parallel mode

[Inkdpixels]

If you execute a command in a lot of your packages and it failed in one of them, the error output might not be completely visible which creates more effort for the developer since he has to cd into the failed package and re-run the command again to see the full output.

It would be cool if the whole output of the failed command would be printed after the summary.

[guigrpa]

It's true, and something I've encountered myself, but I don't have a clear solution to that — in the more general case, each parallel thread may be infinite (e.g. watching over N parallel compilations). In such a case, the error can also be hidden.

For your particular case, you may consider running in non-parallel mode?

[Inkdpixels]

@guigrpa meh, running in non-parallel mode would slow down the CI pipeline a lot, don't you think there is some possibility to print the error logs after all processes have been finished? Of course that doesn't take infinite processes into account, but those are mostly dev scripts anyway aren't they? :)

Anyway thanks for getting back to me so fast! Really appreciated! ❤️

[guigrpa]

I'll figure out something and keep you posted.

You say you're using parallel mode in CI? No problems with the logs? I don't remember exactly how they looked like in e.g. the Travis console, but I guess quite messy, right? What's your experience?

[Inkdpixels]

@guigrpa Yep, IMO the logs are fine, except for the errors, that's why I created this issue. It would also be awesome if each printed log would have a package prefix like Lerna has implemented but that's another issue to open up I guess 😄

[guigrpa]

Please check out v1.2.1, just published, and tell me what you think!

[guigrpa]

Just a note: error messages are reprinted at the end when running in --parallel and also logging in parallel. It doesn't make sense to dump stderr again when the --no-parallel-logs is set, since the error is well visible.

I also added prefixes to the logs when running in --parallel with --no-parallel-logs, to simplify attribution.