Hey, thanks for the detailed report. Your analysis is pretty much spot on.
This is a known limitation of Agent Window Glass. Dev Containers, same as WSL, are not in the list of remote extensions that Glass can start yet. So even after Install and Reload, the extension gets filtered out during scanning, the prompt loops, and the agent exec provider never registers. That is why you see ERROR_EXTENSION_HOST_TIMEOUT after 30 seconds. It is expected that Editor Window works in the same container because the allowlist does not apply there.
Workarounds for now:
- Open the project in classic mode:
cursor --classic - Or from the Glass window run the command Open Editor Window. This will open a classic window where Dev Containers resolve as usual
The team is rolling out remote support in Glass step by step. They started with SSH. Dev Containers are on the radar, but I do not have an ETA right now. If you want to follow the discussion, here is the canonical thread: Dev container remotes don't work with Glass. I will close this as a duplicate to keep the discussion in one place.