[arloor]

Summary

• run extension installation for an already-running server through the platform-aware script launcher
• pass extension flags as individual arguments instead of building a shell command string
• cover Windows and non-Windows command construction with a unit test

Root cause

do_extension_install_on_running_server always invoked bash -c, including when the remote host was Windows. On the affected Windows host, bash resolved to the WindowsApps alias and failed with OS error 1920. A Git Bash installation would also interpret backslashes in the Windows command path as escapes.

This path is used when reconnecting to an existing server, which explains why the first connection succeeds and the second connection fails.

The fix reuses new_script_command, which invokes cmd /Q /C <script> on Windows and executes the script directly on other platforms.

Fixes microsoft/vscode-remote-release#11403

Validation

• cargo test — 64 tests passed
• cargo clippy -- -D warnings
• rustfmt --edition 2021 --check src/tunnels/code_server.rs
• reproduced the failure on the affected Windows host with bash -c
• verified the equivalent cmd /Q /C code-server.cmd --version and --list-extensions --show-versions commands exit successfully on that host

[Copilot]

🟡 Not ready to approve

The doc comment above the new builder function now mis-describes it while the consumer function lost its documentation; the fix is otherwise correct and well-tested.

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Pull request overview

This PR fixes extension installation when the CLI reconnects to an already-running server on Windows. Previously do_extension_install_on_running_server always invoked bash -c, which fails on Windows hosts (resolving to the WindowsApps bash alias / OS error 1920, or mangling backslashes under Git Bash). The fix routes the install through the existing platform-aware new_script_command helper (which runs cmd /Q /C <script> on Windows and the script directly elsewhere) and passes extension flags as separate arguments instead of a shell string.

Changes:

• Extract new_extension_install_command, which builds the install command via new_script_command and appends --install-extension=<id> args individually.
• Replace the bash -c invocation with .output() on the new command, mapping IO errors to CodeError::CommandFailed; drop the now-unused capture_command import.
• Add a unit test asserting the constructed program/args differ correctly on Windows vs. non-Windows.

File summaries

File	Description
cli/src/tunnels/code_server.rs	Adds a platform-aware command builder for extension installation, switches the running-server install path away from bash -c, drops the unused import, and adds a cross-platform unit test.

Review details

• Files reviewed: 1/1 changed files
• Comments generated: 2
• Review effort level: Balanced

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[arloor]

@microsoft-github-policy-service agree

…

---Original--- From: ***@***.***> Date: Mon, Aug 3, 2026 12:05 PM To: ***@***.***>; Cc: ***@***.******@***.***>; Subject: Re: [microsoft/vscode] Fix extension installation on running Windows servers (PR #328660) microsoft-github-policy-service[bot] left a comment (microsoft/vscode#328660) @arloor please read the following Contributor License Agreement(CLA). If you agree with the CLA, please reply with the following information. @microsoft-github-policy-service agree [company="{your company}"] Options: (default - no company specified) I have sole ownership of intellectual property rights to my Submissions and I am not making Submissions in the course of work for my employer. @microsoft-github-policy-service agree (when company given) I am making Submissions in the course of work for my employer (or my employer has intellectual property rights in my Submissions by contract or applicable law). 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