`vscode.env.shell` might return empty string to extension if fetched very soon after startup

[gjsjohnmurray]

Type: Bug

Seems to be a timing issue. The following steps sometimes reproduce it for me, but success may depend on the performance of your workstation (mine is Windows) and which other extensions are enabled by default.

1. Clone https://github.com/gjsjohnmurray/vscode-extension-samples/tree/show-160694
2. Open the statusbar-sample folder in VS Code
3. Open a Terminal in that folder and run npm install
4. Switch to Debug view, choose the ONLY Extension configuration and run it. This launches with --disable-extensions
5. When Extension Host window appears, look on the right of the status bar. If the repro was successful it will look like this:

If this doesn't happen, try the next steps:

6. End debugging and launch the Extension configuration instead. This launches normally and probably won't trigger the problem:

7. From Command Palette of the EH window, run Developer: Reload With Extensions Disabled. With luck this will cause the problem to happen (see first screenshot).

The extension activates "*", so immediately on startup. The first attempt to get vscode.env.shell happens from its activate method.

If the problem shows, click the status bar panel to get the value again. This time it should succeed.

VS Code version: Code - Insiders 1.72.0-insider (835ace5, 2022-09-12T05:16:16.290Z)
OS version: Windows_NT x64 10.0.22000
Modes:
Sandboxed: Yes

[jrieken]

@Tyriar Looks like you should be using extension host init data for this, not a dynamic value that changes along the way

[Tyriar]

@jrieken wouldn't that mean blocking the extension host launch on the pty host and its profile detection round trip? I believe this has always been like this and the value is dynamic depending on settings/environment.

[jrieken]

yes - either block or make it clear that the value changes, e.g we need an event to signal changes. I am not familiar with how this works, does the shell-value change during a single session?

[Tyriar]

Changing the default shell (via settings or UI) will change the value. Let's track adding this API in this issue:

export namespace env {
	export const onDidChangeShell: Event<string>;
}