Mark `subint`-hanging tests with `skipon_spawn_backend`

Adopt the `@pytest.mark.skipon_spawn_backend('subint',
reason=...)` marker (a617b521) across the suites
reproducing the `subint` GIL-contention / starvation
hang classes doc'd in `ai/conc-anal/subint_*_issue.md`.

Deats,
- Module-level `pytestmark` on full-file-hanging suites:
  - `tests/test_cancellation.py`
  - `tests/test_inter_peer_cancellation.py`
  - `tests/test_pubsub.py`
  - `tests/test_shm.py`
- Per-test decorator where only one test in the file
  hangs:
  - `tests/discovery/test_registrar.py
    ::test_stale_entry_is_deleted` — replaces the
    inline `if start_method == 'subint': pytest.skip`
    branch with a declarative skip.
  - `tests/test_subint_cancellation.py
    ::test_subint_non_checkpointing_child`.
- A few per-test decorators are left commented-in-
  place as breadcrumbs for later finer-grained unskips.

Also, some nearby tidying in the affected files:
- Annotate loose fixture / test params
  (`pytest.FixtureRequest`, `str`, `tuple`, `bool`) in
  `tests/conftest.py`, `tests/devx/conftest.py`, and
  `tests/test_cancellation.py`.
- Normalize `"""..."""` → `'''...'''` docstrings per
  repo convention on a few touched tests.
- Add `timeout=6` / `timeout=10` to
  `@tractor_test(...)` on `test_cancel_infinite_streamer`
  and `test_some_cancels_all`.
- Drop redundant `spawn_backend` param from
  `test_cancel_via_SIGINT`; use `start_method` in the
  `'mp' in ...` check instead.

(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code

tests/conftest.py

@@ -139,7 +139,9 @@ def pytest_addoption(
 
 
 @pytest.fixture(scope='session', autouse=True)
-def loglevel(request) -> str:
+def loglevel(
+    request: pytest.FixtureRequest,
+) -> str:
     import tractor
     orig = tractor.log._default_loglevel
     level = tractor.log._default_loglevel = request.config.option.loglevel
@@ -156,7 +158,7 @@ def loglevel(request) -> str:
 
 @pytest.fixture(scope='function')
 def test_log(
-    request,
+    request: pytest.FixtureRequest,
     loglevel: str,
 ) -> tractor.log.StackLevelAdapter:
     '''

tests/devx/conftest.py

@@ -146,13 +146,12 @@ def spawn(
     ids='ctl-c={}'.format,
 )
 def ctlc(
-    request,
+    request: pytest.FixtureRequest,
     ci_env: bool,
 
 ) -> bool:
 
-    use_ctlc = request.param
+    use_ctlc: bool = request.param
-
     node = request.node
     markers = node.own_markers
     for mark in markers:

tests/discovery/test_registrar.py

@@ -520,8 +520,6 @@ async def kill_transport(
 
 
 
-# @pytest.mark.parametrize('use_signal', [False, True])
-#
 # Wall-clock bound via `pytest-timeout` (`method='thread'`).
 # Under `--spawn-backend=subint` this test can wedge in an
 # un-Ctrl-C-able state (abandoned-subint + shared-GIL
@@ -537,6 +535,16 @@ async def kill_transport(
     3,  # NOTE should be a 2.1s happy path.
     method='thread',
 )
+@pytest.mark.skipon_spawn_backend(
+    'subint',
+    reason=(
+        'XXX SUBINT HANGING TEST XXX\n'
+        'See oustanding issue(s)\n'
+        # TODO, put issue link!
+    )
+)
+# @pytest.mark.parametrize('use_signal', [False, True])
+#
 def test_stale_entry_is_deleted(
     debug_mode: bool,
     daemon: subprocess.Popen,
@@ -549,12 +557,6 @@ def test_stale_entry_is_deleted(
     stale entry and not delivering a bad portal.
 
     '''
-    if start_method == 'subint':
-        pytest.skip(
-            'XXX SUBINT HANGING TEST XXX\n'
-            'See oustanding issue(s)\n'
-        )
-
     async def main():
 
         name: str = 'transport_fails_actor'

tests/test_cancellation.py

@@ -21,6 +21,16 @@ _non_linux: bool = platform.system() != 'Linux'
 _friggin_windows: bool = platform.system() == 'Windows'
 
 
+pytestmark = pytest.mark.skipon_spawn_backend(
+    'subint',
+    reason=(
+        'XXX SUBINT HANGING TEST XXX\n'
+        'See oustanding issue(s)\n'
+        # TODO, put issue link!
+    )
+)
+
+
 async def assert_err(delay=0):
     await trio.sleep(delay)
     assert 0
@@ -110,8 +120,17 @@ def test_remote_error(reg_addr, args_err):
             assert exc.boxed_type == errtype
 
 
+# @pytest.mark.skipon_spawn_backend(
+#     'subint',
+#     reason=(
+#         'XXX SUBINT HANGING TEST XXX\n'
+#         'See oustanding issue(s)\n'
+#         # TODO, put issue link!
+#     )
+# )
 def test_multierror(
     reg_addr: tuple[str, int],
+    start_method: str,
 ):
     '''
     Verify we raise a ``BaseExceptionGroup`` out of a nursery where
@@ -141,15 +160,28 @@ def test_multierror(
         trio.run(main)
 
 
-@pytest.mark.parametrize('delay', (0, 0.5))
 @pytest.mark.parametrize(
-    'num_subactors', range(25, 26),
+    'delay',
+    (0, 0.5),
+    ids='delays={}'.format,
 )
-def test_multierror_fast_nursery(reg_addr, start_method, num_subactors, delay):
+@pytest.mark.parametrize(
-    """Verify we raise a ``BaseExceptionGroup`` out of a nursery where
+    'num_subactors',
+    range(25, 26),
+    ids= 'num_subs={}'.format,
+)
+def test_multierror_fast_nursery(
+    reg_addr: tuple,
+    start_method: str,
+    num_subactors: int,
+    delay: float,
+):
+    '''
+    Verify we raise a ``BaseExceptionGroup`` out of a nursery where
     more then one actor errors and also with a delay before failure
     to test failure during an ongoing spawning.
-    """
+
+    '''
     async def main():
         async with tractor.open_nursery(
             registry_addrs=[reg_addr],
@@ -189,8 +221,15 @@ async def do_nothing():
     pass
 
 
-@pytest.mark.parametrize('mechanism', ['nursery_cancel', KeyboardInterrupt])
+@pytest.mark.parametrize(
-def test_cancel_single_subactor(reg_addr, mechanism):
+    'mechanism', [
+    'nursery_cancel',
+    KeyboardInterrupt,
+])
+def test_cancel_single_subactor(
+    reg_addr: tuple,
+    mechanism: str|KeyboardInterrupt,
+):
     '''
     Ensure a ``ActorNursery.start_actor()`` spawned subactor
     cancels when the nursery is cancelled.
@@ -232,9 +271,12 @@ async def stream_forever():
         await trio.sleep(0.01)
 
 
-@tractor_test
+@tractor_test(
-async def test_cancel_infinite_streamer(start_method):
+    timeout=6,
-
+)
+async def test_cancel_infinite_streamer(
+    start_method: str
+):
     # stream for at most 1 seconds
     with (
         trio.fail_after(4),
@@ -257,6 +299,14 @@ async def test_cancel_infinite_streamer(start_method):
     assert n.cancelled
 
 
+# @pytest.mark.skipon_spawn_backend(
+#     'subint',
+#     reason=(
+#         'XXX SUBINT HANGING TEST XXX\n'
+#         'See oustanding issue(s)\n'
+#         # TODO, put issue link!
+#     )
+# )
 @pytest.mark.parametrize(
     'num_actors_and_errs',
     [
@@ -286,7 +336,9 @@ async def test_cancel_infinite_streamer(start_method):
         'no_daemon_actors_fail_all_run_in_actors_sleep_then_fail',
     ],
 )
-@tractor_test
+@tractor_test(
+    timeout=10,
+)
 async def test_some_cancels_all(
     num_actors_and_errs: tuple,
     start_method: str,
@@ -370,7 +422,10 @@ async def test_some_cancels_all(
         pytest.fail("Should have gotten a remote assertion error?")
 
 
-async def spawn_and_error(breadth, depth) -> None:
+async def spawn_and_error(
+    breadth: int,
+    depth: int,
+) -> None:
     name = tractor.current_actor().name
     async with tractor.open_nursery() as nursery:
         for i in range(breadth):
@@ -396,7 +451,10 @@ async def spawn_and_error(breadth, depth) -> None:
 
 
 @tractor_test
-async def test_nested_multierrors(loglevel, start_method):
+async def test_nested_multierrors(
+    loglevel: str,
+    start_method: str,
+):
     '''
     Test that failed actor sets are wrapped in `BaseExceptionGroup`s. This
     test goes only 2 nurseries deep but we should eventually have tests
@@ -483,20 +541,21 @@ async def test_nested_multierrors(loglevel, start_method):
 
 @no_windows
 def test_cancel_via_SIGINT(
-    loglevel,
+    loglevel: str,
-    start_method,
+    start_method: str,
-    spawn_backend,
 ):
-    """Ensure that a control-C (SIGINT) signal cancels both the parent and
+    '''
+    Ensure that a control-C (SIGINT) signal cancels both the parent and
     child processes in trionic fashion
-    """
+
+    '''
     pid: int = os.getpid()
 
     async def main():
         with trio.fail_after(2):
             async with tractor.open_nursery() as tn:
                 await tn.start_actor('sucka')
-                if 'mp' in spawn_backend:
+                if 'mp' in start_method:
                     time.sleep(0.1)
                 os.kill(pid, signal.SIGINT)
                 await trio.sleep_forever()
@@ -580,6 +639,14 @@ async def spawn_sub_with_sync_blocking_task():
         print('exiting first subactor layer..\n')
 
 
+# @pytest.mark.skipon_spawn_backend(
+#     'subint',
+#     reason=(
+#         'XXX SUBINT HANGING TEST XXX\n'
+#         'See oustanding issue(s)\n'
+#         # TODO, put issue link!
+#     )
+# )
 @pytest.mark.parametrize(
     'man_cancel_outer',
     [
@@ -694,7 +761,7 @@ def test_cancel_while_childs_child_in_sync_sleep(
 
 
 def test_fast_graceful_cancel_when_spawn_task_in_soft_proc_wait_for_daemon(
-    start_method,
+    start_method: str,
 ):
     '''
     This is a very subtle test which demonstrates how cancellation

tests/test_inter_peer_cancellation.py

@@ -26,6 +26,15 @@ from tractor._testing import (
 
 from .conftest import cpu_scaling_factor
 
+pytestmark = pytest.mark.skipon_spawn_backend(
+    'subint',
+    reason=(
+        'XXX SUBINT GIL-CONTENTION HANGING TEST XXX\n'
+        'See oustanding issue(s)\n'
+        # TODO, put issue link!
+    )
+)
+
 # XXX TODO cases:
 # - [x] WE cancelled the peer and thus should not see any raised
 #   `ContextCancelled` as it should be reaped silently?

tests/test_pubsub.py

@@ -7,6 +7,14 @@ import tractor
 from tractor.experimental import msgpub
 from tractor._testing import tractor_test
 
+pytestmark = pytest.mark.skipon_spawn_backend(
+    'subint',
+    reason=(
+        'XXX SUBINT HANGING TEST XXX\n'
+        'See oustanding issue(s)\n'
+        # TODO, put issue link!
+    )
+)
 
 def test_type_checks():
 

tests/test_shm.py

@@ -14,6 +14,14 @@ from tractor.ipc._shm import (
     attach_shm_list,
 )
 
+pytestmark = pytest.mark.skipon_spawn_backend(
+    'subint',
+    reason=(
+        'XXX SUBINT GIL-CONTENTION HANGING TEST XXX\n'
+        'See oustanding issue(s)\n'
+        # TODO, put issue link!
+    )
+)
 
 @tractor.context
 async def child_attach_shml_alot(

tests/test_subint_cancellation.py

@@ -161,6 +161,14 @@ def test_subint_happy_teardown(
         trio.run(partial(_happy_path, reg_addr, deadline))
 
 
+@pytest.mark.skipon_spawn_backend(
+    'subint',
+    reason=(
+        'XXX SUBINT HANGING TEST XXX\n'
+        'See oustanding issue(s)\n'
+        # TODO, put issue link!
+    )
+)
 # Wall-clock bound via `pytest-timeout` (`method='thread'`)
 # as defense-in-depth over the inner `trio.fail_after(15)`.
 # Under the orphaned-channel hang class described in