Remote SSH workspace paths are handled locally in Copilot Chat UI mode, causing repeated tool failures and renderer overload

[metaversetimes]

Does this issue occur when all extensions are disabled?: No

• VS Code Version: 1.112.0
• OS Version: macOS 15.7.3

Steps to Reproduce:

1. Open VS Code on macOS and connect to a Linux host using Remote SSH.
2. Open a remote workspace, for example /home/xxx/ogw4.
3. Configure GitHub Copilot Chat to run in UI/local mode.
4. Use Copilot Chat in a workflow that invokes filesystem tools, such as agent/edit mode.
5. Ask Copilot Chat to inspect or read files from the remote workspace.
6. Observe that Copilot Chat attempts to access remote paths such as /home/xxx/ogw4/... using the local filesystem.
7. Errors like the following appear in the Copilot Chat logs:
   • File /home/xxx/ogw4/src/module/ogw_upstream_worker.cpp does not exist
   • ENOENT: no such file or directory, scandir '/home/xxx/ogw4'
8. At the same time, the Code Helper (Renderer) process shows very high resource usage and VS Code becomes laggy.

Expected behavior:

When Copilot Chat is intentionally running in UI/local mode against a Remote SSH workspace, it should not repeatedly invoke local filesystem tools on remote paths. It should either proxy those requests to the remote side, reject them cleanly, or stop retrying.

Actual behavior:

Copilot Chat repeatedly issues local filesystem requests against remote Linux paths, causing repeated tool failures and severe renderer load. In the observed case, renderer CPU reached about 156.5% and memory usage grew to about 2.2 GB.

Additional information:

• Extension bisect narrowed the issue down to GitHub Copilot Chat.
• GitHub Copilot Chat version: 0.40.1
• This is not a case where UI mode is unexpected. UI/local mode is explicitly configured.
• The suspected bug is incorrect handling of Remote SSH workspace paths while running in UI mode, plus inefficient failure/retry behavior after those tool calls fail.

[chrmarti]

Thanks for the detailed report. This is the same Remote-SSH UI-mode path-resolution defect tracked by #284417; the macOS reproduction and renderer CPU/memory measurements here are useful additional evidence for that investigation.

/duplicate of #284417