1 commit

Author	SHA1	Message	Date
quentinmaisonneuve	6cba4419d0	fix(wrap): detach the shared proxy on Windows so it survives an ungraceful agent close (#1464) ... ## Description Closing one `headroom wrap <agent>` instance on Windows could kill the **shared proxy** out from under every other running instance, so their requests started failing. `_start_proxy` launched the proxy as a child of whichever agent started it first, without detaching it from that agent's console and Job object. The wrapper already reference-counts clients via per-PID markers and `_make_cleanup` leaves the proxy running while other clients exist — but that only runs on a *graceful* exit. On an *ungraceful* close (closing the terminal window, `taskkill`, a crash) Windows tree-kills the whole process group/Job and the proxy dies directly, bypassing the reference counting. Every other instance's `ANTHROPIC_BASE_URL` then points at a dead `127.0.0.1:8787`, so all of its API traffic fails. ## Type of Change - [x] Bug fix (non-breaking change that fixes an issue) - [ ] New feature (non-breaking change that adds functionality) - [ ] Breaking change (fix or feature that would cause existing functionality to change) - [ ] Documentation update - [ ] Performance improvement - [ ] Code refactoring (no functional changes) ## Changes Made - `_start_proxy` creates the proxy with `DETACHED_PROCESS | CREATE_NEW_PROCESS_GROUP | CREATE_BREAKAWAY_FROM_JOB` on Windows, so an ungraceful close of the launching agent can no longer reach it; only the ref-counted `_make_cleanup` ends the proxy. - Falls back without `CREATE_BREAKAWAY_FROM_JOB` (catching `OSError`) when the launcher's Job forbids breakaway; `DETACHED_PROCESS` still spares the proxy from console-close events. - Platform guard is `sys.platform == "win32"` (not `os.name == "nt"`) so mypy narrows the platform and resolves the Windows-only `subprocess` constants. - POSIX path unchanged: `creationflags=0`, detachment still via `start_new_session` (`setsid`). - Added `tests/test_cli/test_wrap_proxy_detach.py` and a CHANGELOG Bug Fixes entry. ## Testing - [x] Unit tests pass (`pytest`) - [x] Linting passes (`ruff check .`) - [x] Type checking passes (`mypy headroom`) - [x] New tests added for new functionality - [x] Manual testing performed ### Test Output ```text $ pytest tests/test_cli/test_wrap_proxy_detach.py -q .. [100%] 2 passed, 2 warnings in 1.50s $ ruff check headroom/cli/wrap.py tests/test_cli/test_wrap_proxy_detach.py All checks passed! $ mypy --follow-imports=silent headroom/cli/wrap.py tests/test_cli/test_wrap_proxy_detach.py Success: no issues found ``` ## Real Behavior Proof - Environment: Windows 11, Python 3.11.9, headroom-ai (pipx). Two concurrent `headroom wrap claude` instances sharing proxy `127.0.0.1:8787`. `_start_proxy` was also exercised directly on this host with `subprocess.Popen` stubbed. - Exact command / steps: (1) start two `headroom wrap claude` instances; (2) close the terminal window of the one that started the proxy (ungraceful — not `/exit`); (3) issue a request from the surviving instance. Separately: call `_start_proxy(8787)` with `subprocess.Popen` stubbed and read back the creation flags. - Observed result: before the fix the proxy died with the closed window and the surviving instance failed (`ANTHROPIC_BASE_URL` → dead `:8787`), because the OS tree-killed the child before the ref-count path could spare it. After the fix the detached proxy survives the close and the surviving instance keeps working; the stub harness reports `creationflags=0x1000208` (`DETACHED_PROCESS | CREATE_NEW_PROCESS_GROUP | CREATE_BREAKAWAY_FROM_JOB`) on win32 and `0` when forced off-Windows. - Not tested: real breakaway behavior under an actual restrictive Job object on this host (the OS-level effect). The `OSError` fallback path itself now has a dedicated unit test (`test_start_proxy_retries_without_breakaway_when_job_forbids_it`). ## Review Readiness - [x] I have performed a self-review - [x] This PR is ready for human review ## Checklist - [x] My code follows the project's style guidelines - [x] I have performed a self-review of my code - [x] I have commented my code, particularly in hard-to-understand areas - [ ] I have made corresponding changes to the documentation - [x] My changes generate no new warnings - [x] I have added tests that prove my fix is effective or that my feature works - [x] New and existing unit tests pass locally with my changes - [x] I have updated the CHANGELOG.md if applicable ## Screenshots (if applicable) N/A — no UI changes. ## Additional Notes - Documentation checklist item is N/A: this is a behavioral bug fix with no user-facing doc surface. - Scope is the single `subprocess.Popen` call in `_start_proxy`; the marker-based reference counting in `_make_cleanup` is unchanged and remains the only thing that intentionally stops the proxy.	2026-06-30 13:49:28 -05:00