Extend the pytest plugin with helpers that detect
and adapt to `--capture=sys` under fork-based
spawners (`main_thread_forkserver`, `mp_forkserver`)
where fd-capture causes hangs.
Deats,
- track `_cap_sys_passed_as_flag` + `_cap_fd_set`
globals in `pytest_load_initial_conftests()`.
- add `@pytest.hookimpl(tryfirst=True)` + re-parse
args after appending `--capture=sys`.
- `_is_forking_spawner()` predicate + fixture.
- `maybe_xfail_for_spawner()` — enalbes skipping tests that need capsys
but weren't passed `--capture=sys`.
- `set_fork_aware_capture` fixture — returns the appropriate capture
fixture per spawner backend based on `start_method: str` set via CLI.
- wire `set_fork_aware_capture` into `tractor_test`
wrapper's fixture injection.
Also,
- add `alert_on_finish` session fixture (terminal
bell on completion; tho not sure it works fully..)
- add `ids=` to `start_method` parametrize.
- restore `default=False` on `--enable-stackscope`.
- drop commented-out `--ll` option block; we will likely factor it to
our plugin eventually however..
(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit d549c72052)
Under `main_thread_forkserver` the bootstrapping
hook switches to `--capture=sys`, so subactor
fd-level output (tree dumps, zombie-reaper msgs)
isn't captured per-test by pexpect. Gate those
expects behind a `no_capfd` check so the test
passes on both capture modes.
(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 5a9926fc32)
Only override `tractor.log._default_loglevel` when
the flag is explicitly passed — lets per-spawn and
per-example `loglevel` kwargs take effect instead
of being clobbered by the hard-coded `'ERROR'`
default.
(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 72a0465c52)
Pass explicit `loglevel` to `spawn()` calls in
`test_debugger` tests — required for pexpect
pattern matching now that examples no longer
hard-code log levels.
Also,
- make `expect()` return the decoded `before` str.
- add `start_method` param + fork-backend timeout
slack (+4s) in nested-error test.
- clean up debug examples: drop unused loglevels,
rename `n` -> `an`, fix docstrings, add TODO
comments for tpt parametrize via osenv.
(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 9431a81d37)
Add `disable_pdbp_color()` to the `sync_bp` example
to suppress pygments prompt coloring when
`PYTHON_COLORS=0` — makes pexpect pattern matching
deterministic.
Deats,
- set `loglevel='pdb'` in both script + test spawn.
- disable `enable_stack_on_sig` in example, assert
no `stackscope` output in test.
- update `attach_patts` keys/values with `|_<Task`
/ `|_<Thread` / `|_('subactor'` prefixes to match
actual tree-dump format.
- add call-site patterns (`tractor.pause_from_sync()`
`tractor.pause()`, `breakpoint(hide_tb=...)`).
- trim trailing `\n` from `Lock.repr()` output.
(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit fc2e298a29)
Track `stackscope` enablement in `RuntimeVars` so
the flag propagates to subactors via the standard
rtvar IPC path instead of relying solely on the
`TRACTOR_ENABLE_STACKSCOPE` env var.
Deats,
- add `use_stackscope: bool` to `RuntimeVars`
struct + defaults dict
- `enable_stack_on_sig()` sets the rtvar on
successful `stackscope` import, asserts unset
on `ImportError`
- nest stackscope init under `_debug_mode` gate
in `Actor.async_main`, check rtvar alongside
env var
- defer `maybe_init_greenback` import to its own
`use_greenback` branch
(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 48523358cf)
Factor the sub-actor relay loop out of
`dump_tree_on_sig()` into `_relay_sig_to_subactors()`
and chain both dump + relay in a single
`run_sync_soon` callback (`_dump_then_relay`) so the
parent's task-tree flushes BEFORE any sub receives
the signal — fixes a hierarchical-ordering race
where subs could dump ahead of the parent in the
muxed pty stream.
Also,
- gate file/tty sink writes behind `write_file` +
`write_tty` params on `dump_task_tree()`.
- use `actor.aid.uid` instead of deprecated `.uid`.
- update `test_shield_pause` expects to match the
new sequential parent -> relay-log -> sub ordering.
(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit e2b790a70d)
Move `--capture=sys` enforcement from a static ini
flag to a `pytest_load_initial_conftests()` bootstrap
hook that dynamically flips capture mode only when a
fork-based spawner (like `main_thread_forkserver`) is
detected; non-fork backends keep `--capture=fd`.
Also,
- load `tractor._testing.pytest` via `-p` in ini
(bc bootstrapping hooks must register before
conftest `pytest_plugins` runs).
- register `_reap` as sub-plugin via `pytest_plugins`
tuple in `._testing.pytest`.
- drop now-duplicate reap fixtures (already in `_reap`
per 1cdc7fb3).
- rename `tractor_enable_stackscope` dest -> `enable_stackscope`
and pop env var on disable.
(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 61d4525137)
Wire up `find_orphaned_uds()` + `reap_uds()` from
`_reap` as a new phase-3 UDS sweep in the CLI
script. Opt-in via `--uds` (run after proc reap +
shm) or `--uds-only` (skip other phases).
Also,
- consolidate skip-proc-reap logic into a single
`skip_proc_reap` bool covering both `--shm-only`
and `--uds-only`
- extend header docstring + usage examples
(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 0996a83655)
Extend the `_testing._reap` mod with UDS sock-file leak detection +
cleanup, complementing the existing shm and subactor-process
reaping:
- `get_uds_dir()`, `_parse_uds_name()`, `find_orphaned_uds()`,
`reap_uds()` — detect `<name>@<pid>.sock` files under
`${XDG_RUNTIME_DIR}/tractor/` whose binder pid is dead (including
the `1616` registry sentinel).
- `_reap_orphaned_subactors` session-scoped autouse fixture: SIGINT
lingering subactors, wait, SIGKILL survivors, then sweep orphaned
UDS files.
- `_track_orphaned_uds_per_test` fn-scoped autouse fixture:
snapshot sock-file dir before/after each test, warn + reap new
orphans to prevent cascade flakiness under `--tpt-proto=uds`.
- `reap_subactors_per_test` opt-in fn-scoped fixture for modules
with known-leaky teardown.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 1cdc7fb302)
In `tests/devx/conftest.py::spawn`, refactor the
fixture-internal closures so consumer tests can pass
explicit `start_method`/`loglevel` to each `_spawn()`
invocation rather than only inheriting the fixture-
scoped parametrize values.
Deats,
- promote `set_spawn_method()` and `set_loglevel()`
to take their respective values as fn params (vs
closing over the fixture-scope vars).
- give `_spawn()` `start_method=start_method` and
`loglevel: str|None = None` kwargs so callers
override one-off without re-parametrizing the
suite. NOTE: this drops the implicit fixture-
scoped `loglevel` forward — `_spawn()` callers
now must pass `loglevel=...` explicitly.
- TODO: figure out how `--ll <level>` should map to
the default (currently `None` → uses env-var or
tractor default).
- add a docstring to `_spawn()` so its role as the
consumer-facing closure is obvious from `help()`.
Also,
- `assert_before()` now returns the `.before` output
on success (was `None`); add a one-line docstring
describing the new return contract.
(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 486249d74f)
In `pyproject.toml`,
- include the `sync_pause` group from `dev`, so dev
installs ship `greenback` for `pause_from_sync()`.
Comment out per-test `@pytest.mark.timeout(...)`
markers in,
- `tests/devx/test_debugger.py`
- `tests/discovery/test_registrar.py`
- `tests/spawn/test_main_thread_forkserver.py`
- `tests/spawn/test_subint_cancellation.py`
- `tests/test_advanced_streaming.py`
- `tests/test_cancellation.py`
The global cap was already dropped (3c366cac); these
were the leftover per-test caps which now block
interactive `pdb` flows under the new spawn backends.
In `uv.lock`,
- pull `greenback` into the resolved `dev` deps
(per the `sync_pause` include above).
- catch up the prior `xonsh` editable→PyPI switch
(from the `pyproject.toml` `tool.uv.sources` edit).
(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit b7115fc875)
(factored: dropped spawn-backend-only paths under tests/spawn/)
Add env-var overrides inside `._root.open_root_actor()` so
devs/test-runs can swap the actor-spawn backend or crank
console verbosity *without* touching application code.
In `._root.open_root_actor()`,
- read `TRACTOR_LOGLEVEL` early, overriding any caller-passed
`loglevel` and stashing an `env_ll_report` to emit once the
console log is set up.
- pull the `loglevel` fallback (`or _default_loglevel`) and
`log.get_console_log()` init *up* so the env-var report
routes through tractor's own logger.
- read `TRACTOR_SPAWN_METHOD`, overriding any caller-passed
`start_method` and warn-logging when the env-var clobbers
an explicit caller value.
Wire the same vars through `tests/devx/conftest.py::spawn`,
- request the `loglevel` fixture, set both `TRACTOR_LOGLEVEL`
and `TRACTOR_SPAWN_METHOD` in `os.environ` before each
`pexpect.spawn()` (inherited by the example subproc).
- expand `supported_spawners` to include
`main_thread_forkserver` and `subint_forkserver` bc
example scripts no longer need per-script CLI plumbing.
- pop both vars in fixture teardown so a leaked value can't
re-route a later in-process tractor test's spawn-backend
or loglevel.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 208e7c0926)
Signal handlers fire in a non-trio stack frame; calling
`stackscope.extract(recurse_child_tasks=True)` from there
only walks the `<init>` task and misses everything inside
`async_main`'s nurseries — exactly the part you want to
see during a hang.
Fix: capture `trio.lowlevel.current_trio_token()` at
`enable_stack_on_sig()` time and stash it as a module-
level `_trio_token`. The SIGUSR1 handler then dispatches
the dump *onto* the trio loop via
`_trio_token.run_sync_soon(_safe_dump_task_tree)`, so
`stackscope.extract` runs from a real trio-task context
and walks the full nursery tree.
Late-binding: pytest's `pytest_configure` calls
`enable_stack_on_sig()` outside any `trio.run`, so token
capture there is a `RuntimeError` — left at `None`. The
runtime re-calls `enable_stack_on_sig()` from inside
`async_main` (subactor side) where the token IS
available, so subactors get the full-tree path.
`dump_tree_on_sig` falls back to a direct call when
`_trio_token is None` (parent process pre-trio.run, or
signal delivered after `trio.run` returns).
`_safe_dump_task_tree()` is a `run_sync_soon`-friendly
wrapper that swallows any exception from
`dump_task_tree()` — trio prints + crashes on uncaught
exceptions in scheduled callbacks; better to log + keep
the run alive so the user can re-trigger.
Other,
- emit `capture-bypass tee: <fpath>` line + `tail -f`
hint in the rendered dump header so users know where
to find the artifact even when stdio is captured.
- swap the inline `f' |_{actor}'` line for a
`_pformat.nest_from_op` rendering of `actor_repr`
(matches the rest of the runtime's nested-op style).
- log lines on handler install + already-installed
branches now note `(trio_token captured: <bool>)`
so it's obvious from the log whether the full-tree
path is wired.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 2d4995e08d)
New `--enable-stackscope` CLI flag installs a SIGUSR1 →
trio-task-tree-dump handler in pytest itself + every
spawned subactor for live stack visibility during hang
investigations. Lighter than `--tpdb` (no pdb machinery
/ tty-lock contention) — pure stack-only triage.
Plumbing:
- `_testing.pytest.pytest_addoption()` adds the flag.
- `_testing.pytest.pytest_configure()` (when flag set):
* exports `TRACTOR_ENABLE_STACKSCOPE=1` so fork-children
inherit it via environ,
* installs the handler in pytest itself via
`enable_stack_on_sig()`.
- `runtime._runtime.Actor.async_main()` extends the
existing `_debug_mode` gate to ALSO fire when
`TRACTOR_ENABLE_STACKSCOPE` is in env — so subactors
install the same handler at runtime startup.
Capture-bypass tee in `dump_task_tree()`:
Pytest's default `--capture=fd` swallows `log.devx()`
output, making SIGUSR1 dumps invisible right when you
need them. Render the dump once to a `full_dump` str,
then unconditionally tee to:
- `/tmp/tractor-stackscope-<pid>.log` (append-mode,
always written) — guaranteed-readable artifact even
under CI / `nohup` / no-tty. `tail -f` to follow.
- `/dev/tty` (best-effort) — pytest never captures the
tty; ignored if device is missing.
Other,
- squelch the benign `RuntimeWarning` ("coroutine method
'asend'/'athrow' was never awaited") from
`stackscope._glue`'s import-time async-gen type
introspection so `--enable-stackscope` setup stays
quiet.
- log msg in the `_runtime` ImportError branch now
mentions `--enable-stackscope` alongside debug-mode.
Usage,
pytest --enable-stackscope -k <hang-test>
# in another shell, find the pid + signal:
kill -USR1 <pytest-or-subactor-pid>
# tail the artifact:
tail -f /tmp/tractor-stackscope-<pid>.log
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 5418f2dc3c)
Mirror `060f7d24`'s pattern (backend-aware timeout in
`maybe_expect_raises`) for `test_dynamic_pub_sub`'s hard
`trio.fail_after` cap. Fork-based backends pay per-spawn
fork+IPC-handshake cost which stacks over `cpus - 1`
sequential `n.run_in_actor()` calls; empirically 12s
flakes on `main_thread_forkserver` under UDS
cross-pytest contention (#451 / #452).
Defaults:
- `main_thread_forkserver` → 30s
- everything else → 12s (unchanged)
Hoist the timeout-pick out of the `main()` closure so the
dispatch happens once in the trio task rather than
re-evaluating per spawn.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 383b0fdd75)
Default `timeout` from `int = 3` → `int|None = None`;
when unset, pick a backend-aware value. Fork-based
backends (`main_thread_forkserver`) need real headroom
bc actor spawn + IPC ctx-exit + msg-validation error
path is much heavier than under `trio` backend —
especially under cross-pytest-stream contention (#451).
Defaults:
- `main_thread_forkserver` → 30s
- everything else → 3s (unchanged)
Empirical flake history that motivated 30s as the floor
on fork backends (all from `test_basic_payload_spec`):
- 3s → all-valid variant flaked w/ `TooSlowError`
- 8s → `invalid-return` variant flaked w/ `Cancelled`
(surfaced instead of `MsgTypeError` bc the
outer `fail_after` fired mid-error-path)
- 15s → flaked under cross-pytest-stream contention
30s gives plenty of headroom while still failing-loud
on a genuine hang. Callers can opt out by passing an
explicit `timeout=` kw.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 060f7d24c4)
`timeout = 200` was firing via SIGALRM (the default
`method='signal'`) which synchronously raises `Failed` in
trio's main thread mid-`epoll.poll()`, abandoning trio's
runner mid-flight and leaving `GLOBAL_RUN_CONTEXT` half-
installed. EVERY subsequent `trio.run()` in the same pytest
session then bails with
`RuntimeError: Attempted to call run() from inside a run()`.
Empirical impact: a session that hits a single 200s hang
cascades into 30-40 false-positive failures across every
downstream test file that uses `trio.run`. Recent UDS run
saw 1 real timeout (`test_unregistered_err_still_relayed`)
poison 38 sibling tests with cascade-fails — a debugging
nightmare.
Same architectural bug we already documented in
`tests/test_advanced_streaming.py::test_dynamic_pub_sub`
(see its module-level NOTE) — both `pytest-timeout`
enforcement modes are incompatible with trio under fork-
based spawn backends. Now scoped session-wide.
For tests that legitimately need a wall-clock cap, the
canonical pattern is `with trio.fail_after(N):` INSIDE the
test — trio's own `Cancelled` machinery cleanly unwinds
the actor nursery without disturbing global state.
For CI: rely on job-level wall-clock timeouts (e.g. GitHub
Actions `timeout-minutes`) to abort genuinely-stuck suites.
`pyproject.toml` comment block spells this all out so a
future contributor doesn't reach back for `timeout =` and
re-introduce the bug.
ALSO, bump `xonsh` to at least `0.23.0` release.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 3c366cac13)
Drop `@pytest.mark.timeout(...)` for the per-test wall-clock
cap on `test_dynamic_pub_sub`; rely on `trio.fail_after(12)`
inside `main()` instead.
Both pytest-timeout enforcement modes are incompatible with
trio under fork-based backends:
- `method='signal'` (SIGALRM) synchronously raises `Failed`
in trio's main thread mid-`epoll.poll()`, leaving
`GLOBAL_RUN_CONTEXT` half-installed ("Trio guest run got
abandoned") so EVERY subsequent `trio.run()` in the same
pytest process bails with
`RuntimeError: Attempted to call run() from inside a run()`
— full-session poison.
- `method='thread'` calls `_thread.interrupt_main()` which
can let the KBI escape trio's `KIManager` under fork-
cascade teardown races and bubble out of pytest entirely
— kills the whole session.
`trio.fail_after()` keeps cancellation inside the trio loop:
- Raises `TooSlowError` cleanly through the open-nursery's
cancel cascade.
- Doesn't disturb any out-of-band signal/thread state.
- Failure stays scoped to the single test — no cross-test
global state corruption either way.
Verified empirically: 10 hammer-runs of `test_dynamic_pub_sub`
go from 5/10 fail (with global-state poison) to 3/10 fail
(no poison, all sibling tests still pass). The ~30%
remaining flake rate is a genuine fork-cancel-cascade
hang — separate from this fix but no longer contaminates.
Module-level NOTE comment explains the rationale so future
readers don't re-introduce the bug.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 530160fa69)
Function-scoped, NON-autouse zombie-subactor reaper for
modules whose teardown is known-leaky enough to cascade-
fail every following test in a session.
Sibling to the autouse session-scoped `_reap_orphaned_subactors`. The
session-scoped one fires at session end — too late to save tests that
follow a hung/leaky test in the suite. The new fixture, opted into via
`pytestmark = pytest.mark.usefixtures(...)`, runs between tests in
a problem-module so a leftover subactor from test N can't squat on
registrar ports / UDS paths / shm segments needed by tests N+1,
N+2, ...
Intentionally NOT autouse — the fixture's presence on a module signals
"this module's teardown leaks; please root-cause instead of relying
forever on cleanup". A visibility-vs-convenience trade picked in favor
of the former.
Apply to `tests/test_infected_asyncio.py` since both recent full-suite
runs (parallel-tpt-proto + TCP-only) showed the cascade originating in
this file's KBI- and SIGINT-flavored tests under
`main_thread_forkserver`. Module-comment names the specific offenders so
future de-flake work has a starting point.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit b376eb0332)
Previously the random port was a default-arg expression
(`_rando_port: str = random.randint(1000, 9999)`) — evaluated
ONCE at module import time, making it a per-process singleton.
Two parallel pytest sessions had a 1/9000 birthday-pair chance
of picking the same port; when it hit, every `reg_addr`-using
test in BOTH runs would cascade-fail with "Address already in
use".
Switch to per-call `random.randint()` salted with `os.getpid()`
so:
- within one session: two calls return distinct ports — e.g.
`test_tpt_bind_addrs::bind-subset-reg` now actually gets two
different reg addrs on the TCP backend (it was silently
duplicating before),
- across parallel sessions: pid salt biases each process's
port choices apart, making cross-run collisions
vanishingly rare.
Drop the bogus `: str` annotation (was always `int`). UDS already gets
per-process isolation via `UDSAddress.get_random()`'s `@<pid>`
socket-path suffix, so no change needed there.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 7c5dd4d033)
After the variant-1 / variant-2 backend split, update remaining
string-match refs to the variant-1 backend so user-visible gates
+ skip-marks + comments name the working backend correctly:
- `tractor._root._DEBUG_COMPATIBLE_BACKENDS`: include
`main_thread_forkserver`, drop the stub-only `subint_forkserver`
entry.
- `tests/test_spawning.py::test_loglevel_propagated_to_subactor`:
capfd-skip flips to `main_thread_forkserver`.
- `tests/test_infected_asyncio.py::test_sigint_closes_lifetime_stack`:
xfail-condition flips to `main_thread_forkserver`.
- `tests/test_shm.py`: drop stale "broken on `main_thread_forkserver`"
reason-text since the `mp.SharedMemory(track=False)`
+ resource-tracker monkey-patch in `.ipc._mp_bs` makes the tests pass;
the skip-mark only fires on plain `subint` now.
- Comment / docstring sweep: `runtime._state`, `runtime._runtime`,
`_testing.pytest`, `_subint.py`, `pyproject.toml`,
`test_cancellation.py`, `test_registrar.py` — refs to variant-1
backend updated.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 205382a39b)
(factored: dropped spawn-backend-only path: tractor/spawn/_subint.py)
Same wire-up pattern as the prior `test_dynamic_pub_sub`
commit: each test that already pulled in `debug_mode`
now also pulls in `reg_addr` and passes
`registry_addrs=[reg_addr]` into `tractor.open_nursery()`,
so the suite's standard registry-addr conventions apply.
Tests touched:
- `test_started_misuse`
- `test_simple_context`
- `test_parent_cancels`
- `test_one_end_stream_not_opened`
- `test_maybe_allow_overruns_stream`
- `test_ctx_with_self_actor`
(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 66f1941f46)
Pull in the `reg_addr`, `debug_mode`, and `test_log`
fixtures so this test follows the same conventions as
the rest of the suite:
- pass `registry_addrs=[reg_addr]` + `debug_mode` into
`tractor.open_nursery()` (so `--tpdb` etc work).
- after the `pytest.raises` block, add `assert err` +
`test_log.exception('Timed out AS EXPECTED')` so the
expected timeout is logged explicitly instead of
swallowed.
Also,
- drop whitespace-only blank lines around the
`subs` param of `consumer()` and `ctx` param of
`one_task_streams_and_one_handles_reqresp()`.
- promote `test_sigint_both_stream_types`'s one-line
docstring to multi-line form.
(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 9b05f659b3)
Seems that when run in-suite it delays more then the so-measured "happy
path" timing; better to have no suite-global interruption then asserting
a fast single test's run.
(cherry picked from commit 65fcfbf224)
Since `tractor.ipc._mp_bs.disable_mantracker()` turns off
`mp.resource_tracker` entirely (see the conc-anal doc
`subint_forkserver_mp_shared_memory_issue.md`), a
hard-crashing actor can leave `/dev/shm/<key>` segments
that nothing else GCs. New `tractor-reap` phase 2 sweeps
them.
Deats,
- `tractor/_testing/_reap.py`: add `find_orphaned_shm()`
+ `reap_shm()` helpers. Match criteria: regular file
under `/dev/shm`, owned by current uid, AND no live
proc has it open (mmap'd or fd-held). In-use
enumeration via `psutil.Process.memory_maps()` +
`.open_files()` — xplatform, kernel-canonical (same
answer `lsof` would give), no reliance on
tractor-specific shm-key naming.
- `_ensure_shm_supported()` guard: helpers raise
`NotImplementedError` outside Linux/FreeBSD bc macOS
POSIX shm has no fs-visible path (`shm_open` only)
and Windows is a different story.
- `scripts/tractor-reap`: new `--shm` (run after
process reap) and `--shm-only` (skip process phase)
flags. `-n` dry-runs both phases. Exit code is `1`
if either phase had survivors/errors.
- `pyproject.toml` + `uv.lock`: add `psutil>=7.0.0` to
the `testing` dep group; lazy-imported in `_reap.py`
so the process-reap path stays import-clean without
it.
Also,
- doc `--shm` in `.claude/skills/run-tests/SKILL.md`
(new section 10c) — covers match criteria + the
preservation guarantee for unrelated apps.
- flip mitigation status in
`subint_forkserver_mp_shared_memory_issue.md` from
"could extend `tractor-reap`" to "implemented", with
a note that callers should still UUID-pin shm keys to
avoid cross-session collisions.
Verified locally vs 81 in-use segments held by `piker`,
`lttng-ust-*`, `aja-shm-*` — all preserved; only the
genuinely-orphaned tractor segments got unlinked.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 4f12d69b41)
(factored: dropped subint_forkserver conc-anal doc update)
Implements the resolution described in c99d475d's
`subint_forkserver_mp_shared_memory_issue.md` (now
updated with the resolution post-mortem). Two-part
fix that side-steps `mp.resource_tracker` entirely
rather than try to make it fork-safe — turns out
that's both simpler AND more correct given tractor
already SC-manages allocation lifetimes.
Deats,
- `tractor/ipc/_mp_bs.py::disable_mantracker()`: drop the
`platform.python_version_tuple()[:-1] >= ('3', '13')` branch — patches
now run unconditionally:
* monkey-patch `mp.resource_tracker. _resource_tracker` to a no-op
`ManTracker` subclass (empty `register` / `unregister`
/ `ensure_running`).
* return `partial(SharedMemory, track=False)` for the per-allocation
opt-out.
* belt + suspenders: even if something dodges the wrapper, the
singleton can't talk to the inherited (broken) parent fd.
- `tractor/ipc/_shm.py::open_shm_list()`: drop the 3.13+ conditional
skip of the unlink-callback; install a `try_unlink()` wrapper that
swallows `FileNotFoundError` (sibling-already-cleaned race in
shared-key setups). Without `mp.resource_tracker` doing it for us, we
own the unlink — `actor. lifetime_stack` is the right place since
tractor already controls actor lifecycle.
- `tests/test_shm.py`: uncomment-out `subint_forkserver` from the
module-level skip- list (tests pass now). Inline comment cross-refs
the two `_mp_bs` / `_shm` workarounds.
- `ai/conc-anal/subint_forkserver_mp_shared_memory_ issue.md`: heavy
rewrite — flips status from "open / unresolvable in tractor" to
"resolved, kept as decision record". Adds Resolution section, "Why
this is the right call" rationale (mp tracker is widely criticized;
tractor already owns lifecycle), trade-offs (crash-leaked segments,
lost mp leak warning), verification (7 passed under both
`subint_forkserver` and `trio` backends), and upstream issue links
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit aa3e230926)
(factored: dropped subint_forkserver conc-anal doc update)
New `ai/conc-anal/` doc: `mp.SharedMemory` is
fork-without-exec unsafe — child inherits parent's
`resource_tracker` fd → EBADF on first shm op;
leaked `/shm_list` cascades `FileExistsError`
across parametrize variants. Canonical CPython
issue class, NOT a tractor bug. Includes two
longer-term mitigation paths (reset inherited
tracker fd vs migrate off `mp.shared_memory`).
Also, update `tests/test_shm.py`:
- comment out `subint_forkserver` from skip list
- rewrite reason with precise failure-mode
descriptions + link to the analysis doc
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit c99d475d03)
(factored: dropped spawn-backend-only paths: ai/conc-anal/subint_forkserver_mp_shared_memory_issue.md)
New `scripts/tractor-reap` CLI wraps the
`_testing._reap` mod for manual zombie-subactor
cleanup after crashed pytest sessions. Two modes:
- orphan-mode (default): finds PPid==1 procs
with cwd matching repo root + `python` in
cmdline.
- descendant-mode (`--parent <pid>`): scoped
sweep under a still-live supervisor.
SC-polite: SIGINT with bounded grace window
(default 3s) before escalating to SIGKILL.
Exit code signals whether escalation was needed
(useful for CI health-checks).
Also, document both the auto-reap fixture and
the CLI in `/run-tests` SKILL.md (section 10).
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 6d76b60404)
Zombie-subactor cleanup for the test suite, SC-polite discipline
(`SIGINT` first, bounded grace, `SIGKILL` only on survivors). Two parts:
a shared reaper module + an autouse session-end fixture that runs it.
Deats,
- new `tractor/_testing/_reap.py` (+230 LOC) — Linux- only reaper using
`/proc/<pid>/{status,cwd,cmdline}` inspection. Two detection modes:
- `find_descendants(parent_pid)` for the in-session case
(PPid-direct-match while pytest is still alive).
- `find_orphans(repo_root)` for the CLI / post- mortem case (`PPid==1`
reparented to init + `cwd` filter to repo root + `python` cmdline
filter).
- `reap(pids, *, grace=3.0, poll=0.25)` does the signal ladder: SIGINT
all, poll up to `grace` for exit, SIGKILL any survivors. Returns
`(signalled, killed)` for caller-side reporting.
- new `_reap_orphaned_subactors` session-scoped autouse fixture in
`tractor/_testing/pytest.py` — after `yield`, runs
`find_descendants(os.getpid())` + `reap(...)` so each pytest session
leaves no surviving forks.
- companion CLI scaffolding lives at `scripts/tractor-reap` (separate
commit) for the pytest-died-mid-session case where the in-session
fixture didn't get to run.
Also,
- promote `from tractor.spawn._spawn import SpawnMethodKey` to
module-top in `pytest.py` (was inline-imported inside
`pytest_generate_tests`), and reuse it in
`pytest_collection_modifyitems` to assert each `skipon_spawn_backend`
mark arg is a valid spawn-method literal — catches typos at collection
time.
- inline `# ?TODO` flags running these through the `try_set_backend`
checker for stronger validation.
Cross-refs `feedback_sc_graceful_cancel_first.md` for the
SIGINT-before-SIGKILL discipline rationale.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit eae478f3d5)
Continues the hygiene pattern from de601676 (cancel tests) into
`tests/test_infected_asyncio.py`: many tests here were calling
`tractor.open_nursery()` w/o `registry_addrs=[reg_addr]` and thus racing
on the default `:1616` registry across sessions. Thread the
session-unique `reg_addr` through so leaked or slow-to-teardown
subactors from a prior test can't cross-pollute.
Deats,
- add `registry_addrs=[reg_addr]` to `open_nursery()`
calls in suite where missing.
- `test_sigint_closes_lifetime_stack`:
- add `reg_addr`, `debug_mode`, `start_method`
fixture params
- `delay` now reads the `debug_mode` param directly
instead of calling `tractor.debug_mode()` (fires
slightly earlier in the test lifecycle)
- sanity assert `if debug_mode: assert
tractor.debug_mode()` after nursery open
- new print showing SIGINT target
(`send_sigint_to` + resolved pid)
- catch `trio.TooSlowError` around
`ctx.wait_for_result()` and conditionally
`pytest.xfail` when `send_sigint_to == 'child'
and start_method == 'subint_forkserver'` — the
known orphan-SIGINT limitation tracked in
`ai/conc-anal/subint_forkserver_orphan_sigint_hang_issue.md`
- parametrize id typo fix: `'just_trio_slee'` → `'just_trio_sleep'`
(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit b350aa09ee)
Lands the capture-pipe workaround from the prior cluster of diagnosis
commits: switch pytest's `--capture` mode from the default `fd`
(redirects fd 1,2 to temp files, which fork children inherit and can
deadlock writing into) to `sys` (only `sys.stdout` / `sys.stderr` — fd
1,2 left alone).
Trade-off documented inline in `pyproject.toml`:
- LOST: per-test attribution of raw-fd output (C-ext writes,
`os.write(2, ...)`, subproc stdout). Still goes to terminal / CI
capture, just not per-test-scoped in the failure report.
- KEPT: `print()` + `logging` capture per-test (tractor's logger uses
`sys.stderr`).
- KEPT: `pytest -s` debugging behavior.
This allows us to re-enable `test_nested_multierrors` without
skip-marking + clears the class of pytest-capture-induced hangs for any
future fork-based backend tests.
Deats,
- `pyproject.toml`: `'--capture=sys'` added to `addopts` w/ ~20 lines of
rationale comment cross-ref'ing the post-mortem doc
- `test_cancellation`: drop `skipon_spawn_backend('subint_forkserver')`
from `test_nested_ multierrors` — no longer needed.
* file-level `pytestmark` covers any residual.
- `tests/spawn/test_subint_forkserver.py`: orphan-SIGINT test's xfail
mark loosened from `strict=True` to `strict=False` + reason rewritten.
* it passes in isolation but is session-env-pollution sensitive
(leftover subactor PIDs competing for ports / inheriting harness
FDs).
* tolerate both outcomes until suite isolation improves.
- `test_shm`: extend the existing
`skipon_spawn_backend('subint', ...)` to also skip
`'subint_forkserver'`.
* Different root cause from the cancel-cascade class:
`multiprocessing.SharedMemory`'s `resource_tracker` + internals
assume fresh- process state, don't survive fork-without-exec cleanly
- `tests/discovery/test_registrar.py`: bump timeout 3→7s on one test
(unrelated to forkserver; just a flaky-under-load bump).
- `tractor.spawn._subint_forkserver`: inline comment-only future-work
marker right before `_actor_child_main()` describing the planned
conditional stdout/stderr-to-`/dev/null` redirect for cases where
`--capture=sys` isn't enough (no code change — the redirect logic
itself is deferred).
EXTRA NOTEs
-----------
The `--capture=sys` approach is the minimum- invasive fix: just a pytest
ini change, no runtime code change, works for all fork-based backends,
trade-offs well-understood (terminal-level capture still happens, just
not pytest's per-test attribution of raw-fd output).
(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 4c133ab541)
(factored: dropped spawn-backend-only paths: tests/spawn/test_subint_forkserver.py + tractor/spawn/_subint_forkserver.py; the xfail-loosening bullet above no longer applies)
Encode the hard-won lesson from the forkserver
cancel-cascade investigation into two skill docs
so future sessions grep-find it before spelunking
into trio internals.
Deats,
- `.claude/skills/conc-anal/SKILL.md`:
- new "Unbounded waits in cleanup paths"
section — rule: bound every `await X.wait()`
in cleanup paths with `trio.move_on_after()`
unless the setter is unconditionally
reachable. Recent example:
`ipc_server.wait_for_no_more_peers()` in
`async_main`'s finally (was unbounded,
deadlocked when any peer handler stuck)
- new "The capture-pipe-fill hang pattern"
section — mechanism, grep-pointers to the
existing `conftest.py` guards (`tests/conftest
.py:258`, `:316`), cross-ref to the full
post-mortem doc, and the grep-note: "if a
multi-subproc tractor test hangs, `pytest -s`
first, conc-anal second"
- `.claude/skills/run-tests/SKILL.md`: new
"Section 9: The pytest-capture hang pattern
(CHECK THIS FIRST)" with symptom / cause /
pre-existing guards to grep / three-step debug
recipe (try `-s`, lower loglevel, redirect
stdout/stderr) / signature of this bug vs. a
real code hang / historical reference
Cost several investigation sessions before the
capture-pipe issue surfaced — it was masked by
deeper cascade deadlocks. Once the cascades were
fixed, the tree tore down enough to generate
pipe-filling log volume. Lesson: **grep this
pattern first when any multi-subproc tractor test
hangs under default pytest but passes with `-s`.**
(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 4106ba73ea)
Refresh the `test_nested_multierrors` skip-mark
reason to the final diagnosis: the hang is pytest's
default `--capture=fd` pipe filling from high-volume
subactor traceback output inherited via fds 1,2 in
fork children — `pytest -s` passes cleanly. Records
the fix direction (redirect child stdio to
`/dev/null` in the fork-child prelude) for whoever
lands the backend.
(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit eceed29d4a)
(factored: kept only the tests/test_cancellation.py skip-reason update of
"Pin forkserver hang to pytest `--capture=fd`"; dropped the subint
conc-anal doc + tests/spawn/test_subint_forkserver.py)
Fifth diagnostic pass pinpointed the hang to
`async_main`'s finally block — every stuck actor
reaches `FINALLY ENTER` but never `RETURNING`.
Specifically `await ipc_server.wait_for_no_more_
peers()` never returns when a peer-channel handler
is stuck: the `_no_more_peers` Event is set only
when `server._peers` empties, and stuck handlers
keep their channels registered.
Wrap the call in `trio.move_on_after(3.0)` + a
warning-log on timeout that records the still-
connected peer count. 3s is enough for any
graceful cancel-ack round-trip; beyond that we're
in bug territory and need to proceed with local
teardown so the parent's `_ForkedProc.wait()` can
unblock. Defensive-in-depth regardless of the
underlying bug — a local finally shouldn't block
on remote cooperation forever.
Verified: with this fix, ALL 15 actors reach
`async_main: RETURNING` (up from 10/15 before).
Test still hangs past 45s though — there's at
least one MORE unbounded wait downstream of
`async_main`. Candidates enumerated in the doc
update (`open_root_actor` finally /
`actor.cancel()` internals / trio.run bg tasks /
`_serve_ipc_eps` finally). Skip-mark stays on
`test_nested_multierrors[subint_forkserver]`.
Also updates
`subint_forkserver_test_cancellation_leak_issue.md`
with the new pinpoint + summary of the 6-item
investigation win list:
1. FD hygiene fix (`_close_inherited_fds`) —
orphan-SIGINT closed
2. pidfd-based `_ForkedProc.wait` — cancellable
3. `_parent_chan_cs` wiring — shielded parent-chan
loop now breakable
4. `wait_for_no_more_peers` bound — THIS commit
5. Ruled-out hypotheses: tree-kill missing, stuck
socket recv, capture-pipe fill (all wrong)
6. Remaining unknown: at least one more unbounded
wait in the teardown cascade above `async_main`
(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit e312a68d8a)
(factored: dropped subint_forkserver conc-anal doc update)
Skip-mark the still-hanging
`test_nested_multierrors[subint_forkserver]` via
`@pytest.mark.skipon_spawn_backend('subint_forkserver',
reason=...)` so it stops blocking the test matrix
while the remaining bug is being chased. The mark is
an inert no-op until that (in-dev) backend lands.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 506617c695)
(factored: kept only the tests/test_cancellation.py skip-mark; dropped
the subint_forkserver conc-anal doc update)
Completes the nested-cancel deadlock fix started in
0cd0b633 (fork-child FD scrub) and fe540d02 (pidfd-
cancellable wait). The remaining piece: the parent-
channel `process_messages` loop runs under
`shield=True` (so normal cancel cascades don't kill
it prematurely), and relies on EOF arriving when the
parent closes the socket to exit naturally.
Under exec-spawn backends (`trio_proc`, mp) that EOF
arrival is reliable — parent's teardown closes the
handler-task socket deterministically. But fork-
based backends like `subint_forkserver` share enough
process-image state that EOF delivery becomes racy:
the loop parks waiting for an EOF that only arrives
after the parent finishes its own teardown, but the
parent is itself blocked on `os.waitpid()` for THIS
actor's exit. Mutual wait → deadlock.
Deats,
- `async_main` stashes the cancel-scope returned by
`root_tn.start(...)` for the parent-chan
`process_messages` task onto the actor as
`_parent_chan_cs`
- `Actor.cancel()`'s teardown path (after
`ipc_server.cancel()` + `wait_for_shutdown()`)
calls `self._parent_chan_cs.cancel()` to
explicitly break the shield — no more waiting for
EOF delivery, unwinding proceeds deterministically
regardless of backend
- inline comments on both sites explain the mutual-
wait deadlock + why the explicit cancel is
backend-agnostic rather than a forkserver-specific
workaround
With this + the prior two fixes, the
`subint_forkserver` nested-cancel cascade unwinds
cleanly end-to-end.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 8ac3dfeb85)
The previous cleanup recipe went straight to
SIGTERM+SIGKILL, which hides bugs: tractor is
structured concurrent — `_trio_main` catches SIGINT
as an OS-cancel and cascades `Portal.cancel_actor`
over IPC to every descendant. So a graceful SIGINT
exercises the actual SC teardown path; if it hangs,
that's a real bug to file (the forkserver `:1616`
zombie was originally suspected to be one of these
but turned out to be a teardown gap in
`_ForkedProc.kill()` instead).
Deats,
- step 1: `pkill -INT` scoped to `$(pwd)/py*` — no
sleep yet, just send the signal
- step 2: bounded wait loop (10 × 0.3s = ~3s) using
`pgrep` to poll for exit. Loop breaks early on
clean exit
- step 3: `pkill -9` only if graceful timed out, w/
a logged escalation msg so it's obvious when SC
teardown didn't complete
- step 4: same SIGINT-first ladder for the rare
`:1616`-holding zombie that doesn't match the
cmdline pattern (find PID via `ss -tlnp`, then
`kill -INT NNNN; sleep 1; kill -9 NNNN`)
- steps 5-6: UDS-socket `rm -f` + re-verify
unchanged
Goal: surface real teardown bugs through the test-
cleanup workflow instead of papering over them with
`-9`.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 70d58c4bd2)
Stopgap companion to d0121960 (`subint_forkserver`
test-cancellation leak doc): five tests in
`tests/test_cancellation.py` were running against the
default `:1616` registry, so any leaked
`subint-forkserv` descendant from a prior test holds
the port and blows up every subsequent run with
`TooSlowError` / "address in use". Thread the
session-unique `reg_addr` fixture through so each run
picks its own port — zombies can no longer poison
other tests (they'll only cross-contaminate whatever
happens to share their port, which is now nothing).
Deats,
- add `reg_addr: tuple` fixture param to:
- `test_cancel_infinite_streamer`
- `test_some_cancels_all`
- `test_nested_multierrors`
- `test_cancel_via_SIGINT`
- `test_cancel_via_SIGINT_other_task`
- explicitly pass `registry_addrs=[reg_addr]` to the
two `open_nursery()` calls that previously had no
kwargs at all (in `test_cancel_via_SIGINT` and
`test_cancel_via_SIGINT_other_task`)
- add bounded `@pytest.mark.timeout(7, method='thread')`
to `test_nested_multierrors` so a hung run doesn't
wedge the whole session
Still doesn't close the real leak — the
`subint_forkserver` backend's `_ForkedProc.kill()` is
PID-scoped not tree-scoped, so grandchildren survive
teardown regardless of registry port. This commit is
just blast-radius containment until that fix lands.
See `ai/conc-anal/
subint_forkserver_test_cancellation_leak_issue.md`.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 1af2121057)
Fork-based backends (esp. `subint_forkserver`) can
leak child actor processes on cancelled / SIGINT'd
test runs; the zombies keep the tractor default
registry (`127.0.0.1:1616` / `/tmp/registry@1616.sock`)
bound, so every subsequent session can't bind and
50+ unrelated tests fail with the same
`TooSlowError` / "address in use" signature. Document
the pre-flight + post-cancel check as a mandatory
step 4.
Deats,
- **primary signal**: `ss -tlnp | grep ':1616'` for a
bound TCP registry listener — the authoritative
check since :1616 is unique to our runtime
- `pgrep -af` scoped to `$(pwd)/py[0-9]*/bin/python.*
_actor_child_main|subint-forkserv` for leftover
actor/forkserver procs — scoped deliberately so we
don't false-flag legit long-running tractor-
embedding apps like `piker`
- `ls /tmp/registry@*.sock` for stale UDS sockets
- scoped cleanup recipe (SIGTERM + SIGKILL sweep
using the same `$(pwd)/py*` pattern, UDS `rm -f`,
re-verify) plus a fallback for when a zombie holds
:1616 but doesn't match the pattern: `ss -tlnp` →
kill by PID
- explicit false-positive warning calling out the
`piker` case (`~/repos/piker/py*/bin/python3 -m
tractor._child ...`) so a bare `pgrep` doesn't lead
to nuking unrelated apps
Goal: short-circuit the "spelunking into test code"
rabbit-hole when the real cause is just a leaked PID
from a prior session, without collateral damage to
other tractor-embedding projects on the same box.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit d093c31979)
The `subint_forkserver` backend's child runtime is trio-native (uses
`_trio_main` + receives `SpawnSpec` over IPC just like `trio`/`subint`),
so `tractor.devx.debug._tty_lock` works in those subactors. Wire the
runtime gates that historically hard-coded `_spawn_method == 'trio'` to
recognize this third backend.
Deats,
- new `_DEBUG_COMPATIBLE_BACKENDS` module-const in `tractor._root`
listing the spawn backends whose subactor runtime is trio-native
(`'trio'`, `'subint_forkserver'`). Both the enable-site
(`_runtime_vars['_debug_mode'] = True`) and the cleanup-site reset
key.
off the same tuple — keep them in lockstep when adding backends
- `open_root_actor`'s `RuntimeError` for unsupported backends now
reports the full compatible-set + the rejected method instead of the
stale "only `trio`" msg.
- `runtime._runtime.Actor._from_parent`'s SpawnSpec-recv gate adds
`'subint_forkserver'` to the existing `('trio', 'subint')` tuple
— fork child-side runtime receives the same SpawnSpec IPC handshake as
the others.
- `subint_forkserver_proc` child-target now passes
`spawn_method='subint_forkserver'` (was hard-coded `'trio'`) so
`Actor.pformat()` / log lines reflect the actual parent-side spawn
mechanism rather than masquerading as plain `trio`.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 8bcbe730bf)
Resetting `_runtime_vars` post-(forking-)spawn was
previously only possible via direct mutation of
`_state._runtime_vars` from an external module + an
inline default dict duplicating the
`_state.py`-internal defaults. Split the access
surface into a pure getter + explicit setter so such
a reset call site becomes a one-liner composition:
`set_runtime_vars(get_runtime_vars(clear_values=True))`.
Deats `tractor/runtime/_state.py`,
- extract initial values into a module-level
`_RUNTIME_VARS_DEFAULTS: dict[str, Any]` constant; the
live `_runtime_vars` is now initialised from
`dict(_RUNTIME_VARS_DEFAULTS)`
- `get_runtime_vars()` grows a `clear_values: bool = False`
kwarg. When True, returns a fresh copy of
`_RUNTIME_VARS_DEFAULTS` instead of the live dict —
still a **pure read**, never mutates anything
- new `set_runtime_vars(rtvars: dict | RuntimeVars)` —
atomic replacement of the live dict's contents via
`.clear()` + `.update()`, so existing references to the
same dict object remain valid. Accepts either the
historical dict form or the `RuntimeVars` struct
(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 7804a9fe57693dd5e15bee6a08e7d2fa14b6a98a)
(factored: kept only the tractor/runtime/_state.py part; dropped
tractor/spawn/_subint_forkserver.py call-site rewire)
Gud Boi