Add support for extracting environment from xonsh.

[jaraco]

Closes #200374.

[jaraco]

I haven't tested this change beyond confirming that xonsh -i -l -c '$[<command>]' works syntactically:

 @ xonsh -i -l -c '$[echo foo]'
foo

Is there a way I can get a build with the change to confirm it fixes the reported issue?

[jaraco]

I read the instructions and figured out how to make a local build of VSCode and ran ./scripts/code.sh, but I couldn't replicate the failure on main. I presume the issue is that the code path isn't triggered when launched from the CLI. I thought I might be able to simulate the non-shell environment by launching with env -i PATH=$PATH ./scripts/code.sh, but even then, the issue doesn't replicate.

Next, I read the code and learned about --force-user-env and using that I was able to replicate the failure. With the patch, the failure still occurs, so I'll need to investigate further.

[jaraco]

By running with --log trace, I can see the command that's being run:

[main 2023-12-17T16:38:29.119Z] getUnixShellEnvironment#shell /Users/jaraco/.local/bin/xonsh
[main 2023-12-17T16:38:29.119Z] getUnixShellEnvironment#spawn ["-i","-l","-c"] $['/Users/jaraco/code/microsoft/vscode/.build/electron/Code - OSS.app/Contents/MacOS/Electron'  -p '"280993a1c165" + JSON.stringify(process.env) + "280993a1c165"']

[jaraco]

When I run that command manually

 @ xonsh -c """$['/Users/jaraco/code/microsoft/vscode/.build/electron/Code - OSS.app/Contents/MacOS/Electron'  -p '"280993a1c165" + JSON.stringify(process.env) + "280993a1c165"']"""

it fails thus:

Text in that image:

Unable to find Electron app at /Users/jaraco/code/microsoft/vscode/"280993a1c165" + JSON.stringify(process.env) + "280993a1c165"

Cannot find module '/Users/jaraco/code/microsoft/vscode/"280993a1c165" + JSON.stringify(process.env) + "280993a1c165"'
Require stack:
- /Users/jaraco/code/microsoft/vscode/.build/electron/Code - OSS.app/Contents/Resources/default_app.asar/main.js
-

[jaraco]

I haven't yet figured out why the invocation of Electron is failing but in c62c575, I replaced the electron invocation with a native JSON rendering of the environment in xonsh, and I've confirmed this approach fixes the issue.

Is this approach acceptable?

Is there any idea why Electron is failing the way it is?

[Tyriar]

As long as the output is identical to the JSON output (or at least parsed in the same way in node), the current approach is fine. It's probably better actually as that way we don't need to launch node.

Let's merge this, please let me know if there are problems with it when it ships as the only way to test this properly is to get a real build post-merge and try launching from the dock.