The Agent/Composer Shell tool returns “no exit status” for every command (even echo hello) and produces zero side effects — no output captured, no files created. The integrated (human-typed) terminal runs the same commands perfectly, so PowerShell, PATH, ExecutionPolicy and all CLI tools are fine. The break is specifically in the agent’s command-execution channel.
Two diagnostics point away from the usual OSC-633 marker theory and toward a deeper spawn-path failure:
Shell integration IS injecting on the interactive side — Get-ChildItem Env:VSCODE* shows VSCODE_INJECTION = 1 plus the full VSCODE_* family. If markers were the issue, the integrated terminal would fail too; it doesn’t.
The agent, asked to inspect its own terminal output, reported “there are no terminal output files to inspect” — i.e. the agent’s pty isn’t being spawned at all, upstream of any marker parsing.
Reproduces identically on PowerShell 5.1 AND Git Bash, ruling out a PowerShell-specific cause.
Already ruled out (none fixed it): full quit + Task Manager-verified restart; Reload Window; shellIntegration.enabled: false; switching profile PowerShell↔Git Bash with kill-all-terminals each time. Toggling settings doesn’t reach it.
Steps to Reproduce
Open any workspace on Windows.
In an Agent chat, ask: Run echo hello
Agent reports “no exit status”; no output captured; no terminal output files produced.
Run echo hello manually in the integrated terminal → returns instantly. The mismatch is the bug.
Expected Behavior
The agent’s Shell tool spawns a pty, runs the command, captures stdout/stderr, and returns exit code 0 within ~1s — the same result the integrated terminal gives.
Hey, thanks for the detailed report. Your diagnosis is spot on. The break is happening above the shell level, so both PowerShell and Git Bash behave the same.
This is a known Windows behavior when Auto-Run is set to Auto-Run in Sandbox. The sandbox helper is not supported on Windows, so the agent exec stream gets closed without an exit event. That’s why you see no exit status and no output or files. The integrated terminal does not use this path, so it works fine.
Workaround:
Settings → Agents → Auto-Run
Switch from Auto-Run in Sandbox to Use Allowlist
Or as an alternative, enable Legacy Terminal Tool. After that, the Shell tool should be able to spawn a pty again and return an exit code.
One note: in newer versions the sandbox option on Windows is hidden, but if you enabled it before, the setting stays and keeps breaking the terminal until you switch it manually. That’s why you still see this on 3.7.42.
For anyone landing here with the same “no exit status / no output / no terminal files” symptom on Windows 3.7.42:
The fix was Settings → Agents → Inline Editing & Terminal → Legacy Terminal Tool (toggle it ON). I left Run Mode on Auto-review.
Worth noting for diagnosis: as you said, the Auto-Run in Sandbox option is now hidden in the UI on 3.7.42, so there was nothing obviously labelled “Sandbox” to switch off — the Run Mode dropdown only showed Allowlist / Auto-review / Run Everything. But the old sandbox value was clearly still active under the hood, because flipping on the Legacy Terminal Tool fixed it instantly.
Verified immediately after toggling: the agent’s Shell tool ran echo hello, pwd, a venv python --version, and git rev-parse — all returned exit code 0 with captured stdout and persistent working directory, in ~500ms each. Both PowerShell and Git Bash now work.
So the takeaway for other Windows users: even if you never see a “Sandbox” option in current builds, if you ever enabled it on an older version, enabling the Legacy Terminal Tool is the switch that gets the pty spawning again. Appreciate the clear diagnosis.
Hey, glad it’s working. And thanks for the detailed follow-up. Your note about the hidden Sandbox option is really helpful.
Quick summary for the user who finds this thread later: on recent builds, the Auto-Run in Sandbox option is hidden in the UI, so you won’t see a clear Sandbox toggle. But if you enabled it on an older version, it can stay on in the background and keep breaking the Shell tool. Turning on Legacy Terminal Tool in Settings → Agents → Inline Editing & Terminal brings back normal pty spawning.
If anything similar comes up again, just message me.