Made compilation error colors come through et.

[gaaclarke]

fixes flutter/flutter#147931

environment variable documented in github issue: ninja-build/ninja#2196

screenshot of results

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[gaaclarke]

Ahhhh, nertz! This breaks the gcc path fix since it breaks the regular expression. I'm putting this back into Draft and removing reviewers.

[flutter-dashboard]

This pull request has been changed to a draft. The currently pending flutter-gold status will not be able to resolve until a new commit is pushed or the change is marked ready for review again.

[matanlurey]

I wonder if this is correct, that is, if this should be conditionally set if the current environment is an ANSI terminal with color support.

If it was conditionally set, would we need the parsing and massaging you did above?

[gaaclarke]

The behavior most people follow is if you aren't connected to a tty you don't emit ansi escape sequences. That's the behavior ninja was doing. I can emulate it. It's only a problem if someone wants to run et as a subprocess.

[gaaclarke]

Done, now we only show the colors if stdout supports it or if it has been overwritten with CLICOLOR_FORCE.

[gaaclarke]

If it was conditionally set, would we need the parsing and massaging you did above?

Yes, we still need it because the gcc path fix is a whole different thing that assumed no ansi escape sequences.

[zanderso]

It's good practice with colors to have some way to disable them on the command line. Is there a ninja command line option (that could be plumbed into extraNinjaArgs in another PR) that will override the environment variable?

[gaaclarke]

It's good practice with colors to have some way to disable them on the command line. Is there a ninja command line option (that could be plumbed into extraNinjaArgs in another PR) that will override the environment variable?

I'll duplicate ninja's behavior and use the environment variable. One sec, it's also related to matans comment.

[gaaclarke]

It's good practice with colors to have some way to disable them on the command line. Is there a ninja command line option (that could be plumbed into extraNinjaArgs in another PR) that will override the environment variable?

Done, see #57174 (comment)