tractor/ai/prompt-io/claude/20260702T155006Z_65bf9df5_prompt_io.raw.md

Raw output — GH #473 UDS-on-macOS root-cause session

NOTE: code output is diff-referenced (not copied) per prompt-io diff-ref mode; all generated code is on branch wkt/uds_macos_473 relative to main (65bf9df5).

Diagnostic narrative (verbatim)

Root-cause work proceeded by linux-side simulation since no macOS host is available:

1. Pulled the actual macOS CI failure log from PR #460 run 28343878933 (job 84115107992): the failure is a bare assert 1 == 0 on proc.returncode with NO stderr surfaced — the harness only re-raised when the LAST stderr line contained ‘Error’.

2. Reproduced the stderr-swallow mechanism on linux: any tractor root-actor crash ends stderr with the strict-EG collapse note ( ^^^ this exc was collapsed from a group ^^^ ) which never matches ‘Error’ — so EVERY possible crash was swallowed. (Verified by sabotaging the runtime dir via an over-long XDG_RUNTIME_DIR → OSError: AF_UNIX path too long → rc=1 + swallowed.)

3. Found + proved a macOS-only addr-corruption bug in MsgpackUDSStream.get_stream_addrs(): the (str(), str()) match-arm unconditionally took peername, but on no-autobind platforms (macOS lacks linux’s SO_PASSCRED-triggered autobind) the accept side’s getpeername() is '' → Path('') garbage laddr/raddr on EVERY accepted UDS conn. Simulated on linux by nulling SO_PASSCRED (no autobind → same '' shape): pre-fix the example printed listener sock file: .; post-fix it prints the real registry sockpath. Non-fatal on linux-sim (rc=0), so possibly not the final macOS crasher — the diagnostic patch guarantees the next macOS CI run reveals any remaining layer.

4. Falsified the missing-parent-dir theory: get_rt_dir() already mkdir(parents=True, exist_ok=True)s at import (and macOS TCP CI passes), so ~/Library/Caches/TemporaryItems absence cannot be the crasher. Hardened start_listener()’s bindspace mkdir anyway (custom filedir case + racing actors).

Generated changes (diff pointers)

git diff main..wkt/uds_macos_473 -- tests/test_docs_examples.py

• always raise with FULL subproc stderr (+stdout) on any non-zero example exit; keep legacy last-line ‘Error’ check for zero-rc cases; drop the macOS+CI skip of uds_transport_actor_tree.py (GH #473 next-step).

git diff main..wkt/uds_macos_473 -- tractor/ipc/_uds.py

• get_stream_addrs(): document the autobind semantics (bytes = linux abstract-ns autobind artifact), add no-autobind (str, str) arm picking the non-empty name (peername connect-side, sockname accept-side) with an empty-pair ValueError guard.
• start_listener(): bs.mkdir(parents=True, exist_ok=True).

git diff main..wkt/uds_macos_473 -- .github/workflows/ci.yml

• remove the macos-latest+uds matrix exclude so UDS-on-macOS is exercised by CI (GH #473 next-step).

git diff main..wkt/uds_macos_473 -- examples/uds_transport_actor_tree.py

• docs nit: peer-pid mechanism is SO_PEERCRED on linux, LOCAL_PEERPID on macOS.

Verification (verbatim summary)

• macOS-shape sim (no autobind) + fix: example rc=0 with correct listener sockpath.
• native linux post-fix: example rc=0, autobind arms unchanged.
• sabotage smoke-test: diagnostic patch surfaces the full EG traceback incl. collapse-note line.
• pytest tests/ipc/ tests/test_2way.py tests/discovery/ --tpt-proto uds: 61 passed, 1 TooSlowError flake (test_simple_rpc) that passes solo in 2.2s — attributed to a concurrent full-suite run (other session) loading the host.
• full tests/test_docs_examples.py run pending at raw-file write time (queued behind the concurrent session’s suite).