Lel, revert `AsyncioCancelled` inherit, module..

Turns out it somehow breaks our `to_asyncio` error relay since obvi
`asyncio`'s runtime seems to specially handle it (prolly via
`isinstance()` ?) and it caused our
`test_aio_cancelled_from_aio_causes_trio_cancelled()` to hang..
Further, obvi `unpack_error()` won't be able to find the type def if not
kept inside `._exceptions`..

So given all that, revert the change/move as well as:
- tweak the aio-from-aio cancel test to timeout.
- do `trio.sleep()` conc with any bg aio task by moving out nursery
  block.
- add a `send_sigint_to: str` parameter to
  `test_sigint_closes_lifetime_stack()` such that we test the SIGINT
  being relayed to just the parent or the child.

tests/test_infected_asyncio.py

@@ -289,23 +289,35 @@ async def aio_cancel():
 
     '''
     await asyncio.sleep(0.5)
-    task = asyncio.current_task()
 
     # cancel and enter sleep
+    task = asyncio.current_task()
     task.cancel()
     await aio_sleep_forever()
 
 
 def test_aio_cancelled_from_aio_causes_trio_cancelled(reg_addr):
+    '''
+    When the `asyncio.Task` cancels itself the `trio` side cshould
+    also cancel and teardown and relay the cancellation cross-process
+    to the caller (parent).
 
+    '''
     async def main():
-        async with tractor.open_nursery() as n:
-            await n.run_in_actor(
+
+        an: tractor.ActorNursery
+        async with tractor.open_nursery() as an:
+            p: tractor.Portal = await an.run_in_actor(
                 asyncio_actor,
                 target='aio_cancel',
                 expect_err='tractor.to_asyncio.AsyncioCancelled',
                 infect_asyncio=True,
             )
+            # NOTE: normally the `an.__aexit__()` waits on the
+            # portal's result but we do it explicitly here
+            # to avoid indent levels.
+            with trio.fail_after(1):
+                await p.wait_for_result()
 
     with pytest.raises(
         expected_exception=(RemoteActorError, ExceptionGroup),
@@ -313,7 +325,7 @@ def test_aio_cancelled_from_aio_causes_trio_cancelled(reg_addr):
         trio.run(main)
 
     # might get multiple `trio.Cancelled`s as well inside an inception
-    err = excinfo.value
+    err: RemoteActorError|ExceptionGroup = excinfo.value
     if isinstance(err, ExceptionGroup):
         err = next(itertools.dropwhile(
             lambda exc: not isinstance(exc, tractor.RemoteActorError),
@@ -321,7 +333,8 @@ def test_aio_cancelled_from_aio_causes_trio_cancelled(reg_addr):
         ))
         assert err
 
-    # ensure boxed error is correct
+    # relayed boxed error should be our `trio`-task's
+    # cancel-signal-proxy-equivalent of `asyncio.CancelledError`.
     assert err.boxed_type == to_asyncio.AsyncioCancelled
 
 
@@ -630,6 +643,7 @@ def test_echoserver_detailed_mechanics(
 async def manage_file(
     ctx: tractor.Context,
     tmp_path_str: str,
+    send_sigint_to: str,
     bg_aio_task: bool = False,
 ):
     '''
@@ -687,14 +701,20 @@ async def manage_file(
         # honestly, this REALLY reminds me why i haven't used
         # `asyncio` by choice in years.. XD
         #
-        # await tractor.to_asyncio.run_task(aio_sleep_forever)
-        if bg_aio_task:
         async with trio.open_nursery() as tn:
+            if bg_aio_task:
                 tn.start_soon(
                     tractor.to_asyncio.run_task,
                     aio_sleep_forever,
                 )
 
+            # XXX don't-need/doesn't-make-a-diff right
+            # since we're already doing it from parent?
+            # if send_sigint_to == 'child':
+            #     os.kill(
+            #         os.getpid(),
+            #         signal.SIGINT,
+            #     )
             await trio.sleep_forever()
 
     # signalled manually at the OS level (aka KBI) by the parent actor.
@@ -702,10 +722,18 @@ async def manage_file(
         print('child raised KBI..')
         assert tmp_file.exists()
         raise
-    else:
+
     raise RuntimeError('shoulda received a KBI?')
 
 
+@pytest.mark.parametrize(
+    'send_sigint_to',
+    [
+        'child',
+        'parent',
+    ],
+    ids='send_SIGINT_to={}'.format,
+)
 @pytest.mark.parametrize(
     'bg_aio_task',
     [
@@ -740,6 +768,8 @@ def test_sigint_closes_lifetime_stack(
     tmp_path: Path,
     wait_for_ctx: bool,
     bg_aio_task: bool,
+    debug_mode: bool,
+    send_sigint_to: str,
 ):
     '''
     Ensure that an infected child can use the `Actor.lifetime_stack`
@@ -749,8 +779,11 @@ def test_sigint_closes_lifetime_stack(
     '''
     async def main():
         try:
-            async with tractor.open_nursery() as n:
-                p = await n.start_actor(
+            an: tractor.ActorNursery
+            async with tractor.open_nursery(
+                debug_mode=debug_mode,
+            ) as an:
+                p: tractor.Portal = await an.start_actor(
                     'file_mngr',
                     enable_modules=[__name__],
                     infect_asyncio=True,
@@ -758,6 +791,7 @@ def test_sigint_closes_lifetime_stack(
                 async with p.open_context(
                     manage_file,
                     tmp_path_str=str(tmp_path),
+                    send_sigint_to=send_sigint_to,
                     bg_aio_task=bg_aio_task,
                 ) as (ctx, first):
 
@@ -777,10 +811,13 @@ def test_sigint_closes_lifetime_stack(
                     # shm-buffer leaks in `piker`'s live quote stream
                     # susbys!
                     #
-                    # await trio.sleep(.5)
                     await trio.sleep(.2)
+                    pid: int = (
+                        cpid if send_sigint_to == 'child'
+                        else os.getpid()
+                    )
                     os.kill(
-                        cpid,
+                        pid,
                         signal.SIGINT,
                     )
 
@@ -790,7 +827,7 @@ def test_sigint_closes_lifetime_stack(
                     if wait_for_ctx:
                         print('waiting for ctx outcome in parent..')
                         try:
-                            with trio.fail_after(.7):
+                            with trio.fail_after(1):
                                 await ctx.wait_for_result()
                         except tractor.ContextCancelled as ctxc:
                             assert ctxc.canceller == ctx.chan.uid

tractor/_exceptions.py

@@ -929,6 +929,17 @@ class MessagingError(Exception):
 
     '''
 
+class AsyncioCancelled(Exception):
+    '''
+    Asyncio cancelled translation (non-base) error
+    for use with the ``to_asyncio`` module
+    to be raised in the ``trio`` side task
+
+    NOTE: this should NOT inherit from `asyncio.CancelledError` or
+    tests should break!
+
+    '''
+
 
 def pack_error(
     exc: BaseException|RemoteActorError,