Wrong/previous version of the extension is still used for debugger features after Install From VSIX... and Restart Extension

[sean-mcmanus]

Does this issue occur when all extensions are disabled?: N/A

• VS Code Version:
  Version: 1.101.0-insider (user setup)
  Commit: 1b4b2f8
  Date: 2025-05-30T05:03:59.165Z
  Electron: 35.4.0
  ElectronBuildId: 11602177
  Chromium: 134.0.6998.205
  Node.js: 22.15.0
  V8: 13.4.114.21-electron.0
  OS: Windows_NT x64 10.0.26100

Steps to Reproduce:

1. Install a published version of an extension such as the C/C++ extension 1.25.3.
2. Do Install From VSIX... and use a newer version of the extension that implements a newer feature such as a newer debugger type. We can send you the vsix we used, built from Support LLDB-DAP as a debugger (OSX/Linux/Windows) vscode-cpptools#13569 .
3. Click the Restart Extension (or whatever it's called button in the Extension pane and/or the popup that appears in the bottom right.
4. Try to use a new feature from the extension, in our case the launch.json "cpplldb" debugger type (or F5).

Bug: As shown in the screenshot below, the older version of the extension is still being used (that doesn't support the new "cpplldb" debugger type) even though it reports the version as the new version -- this could cause extension publishers to not actually be testing the VSIX they intend to ship to users (unless they did an explicit Reload Window).

UPDATE: Actually, it seems like only the debugger-related features are using the older version of the VSIX. I'm seeing our language service features use the correct version.

The 1.26.2-dogfood1 vsix adds the "cpplldb" debugger type and it becomes fixed after doing a reload window:

UPDATE: I repro this on Mac too. I can add a new LLDB-DAP configuration in launch.json (made available by the new extension version), but the new cpplldb type squiggles and doesn't work.