[Fix]: Better output when installing with NPM

[edvincent]

Why do you want this feature?

In the postinstall.sh script that is used when installing with npm, we use nested commands to install vscode and its extensions - see code

As reported in #5530 (and more in #5533), installs were passing but actually failing - and only was seen during runtime.

The nested installs were failing, but the errors weren't being bubbled-up... Was only seen when using --foreground-scripts.

What is your suggestion?

• NPM 8 needs to be passed --foreground-scripts to actually see the output of the nested. We should update the doc to show that as a troubleshooting step in here: https://coder.com/docs/code-server/latest/npm#debugging-install-issues-with-npm
• I would expect the overall script to have a non-0 exit code if any of the nested scripts failed (i.e. they themselves had a non-0 exit code) which would make the overall npm install fail. Need to investigate that.

Are there any workarounds to get this functionality today?

• Pass --foreground-scripts and read carefully :(

Are you interested in submitting a PR for this?

Yes

[jsjoeio]

This seems like a nice UX improvement!