.github/workflows/ci.yml

@@ -74,7 +74,7 @@ jobs:
         run: pip install -U . -r requirements-test.txt -r requirements-docs.txt --upgrade-strategy eager
 
       - name: Run tests
-        run: pytest tests/ --spawn-backend=${{ matrix.spawn_backend }} -rs -v
+        run: pytest tests/ --spawn-backend=${{ matrix.spawn_backend }} -rs -v --full-trace
 
   # We skip 3.10 on windows for now due to
   # https://github.com/pytest-dev/pytest/issues/8733

tests/test_debugger.py

@@ -18,10 +18,6 @@ import time
 
 import pytest
 import pexpect
-from pexpect.exceptions import (
-    TIMEOUT,
-    EOF,
-)
 
 from conftest import repodir
 
@@ -376,11 +372,10 @@ def test_multi_subactors(
     spawn,
     ctlc: bool,
 ):
-    '''
+    """
-    Multiple subactors, both erroring and
+    Multiple subactors, both erroring and breakpointing as well as
-    breakpointing as well as a nested subactor erroring.
+    a nested subactor erroring.
-
+    """
-    '''
     child = spawn(r'multi_subactors')
 
     # scan for the pdbpp prompt
@@ -419,16 +414,14 @@ def test_multi_subactors(
     # 2nd name_error failure
     child.expect(r"\(Pdb\+\+\)")
 
-    # XXX: lol honestly no idea why CI is cuck but
+    assert_before(child, [
-    # seems like this likely falls into our unhandled nested
+        "Attaching to pdb in crashed actor: ('name_error_1'",
-    # case and isn't working in that env due to raciness..
+        "NameError",
-    from conftest import _ci_env
+    ])
-    if not ctlc and _ci_env:
+
-        name = 'name_error' if ctlc else 'name_error_1'
+    # before = str(child.before.decode())
-        assert_before(child, [
+    # assert "Attaching to pdb in crashed actor: ('name_error_1'" in before
-            f"Attaching to pdb in crashed actor: ('{name}'",
+    # assert "NameError" in before
-            "NameError",
-        ])
 
     if ctlc:
         do_ctlc(child)
@@ -458,11 +451,11 @@ def test_multi_subactors(
             do_ctlc(child)
 
     # 2nd depth nursery should trigger
-    if not ctlc:
+    # child.sendline('c')
-        assert_before(child, [
+    # child.expect(r"\(Pdb\+\+\)")
-            spawn_err,
+    # before = str(child.before.decode())
-            "RemoteActorError: ('name_error_1'",
+    assert spawn_err in before
-        ])
+    assert "RemoteActorError: ('name_error_1'" in before
 
     # now run some "continues" to show re-entries
     for _ in range(5):
@@ -471,50 +464,31 @@ def test_multi_subactors(
 
     # quit the loop and expect parent to attach
     child.sendline('q')
+    child.expect(r"\(Pdb\+\+\)")
+    before = str(child.before.decode())
 
-    try:
+    # debugger attaches to root
-        child.expect(r"\(Pdb\+\+\)")
+    assert "Attaching to pdb in crashed actor: ('root'" in before
-    except TIMEOUT:
+    # expect a multierror with exceptions for each sub-actor
-        if _ci_env and not ctlc:
+    assert "RemoteActorError: ('breakpoint_forever'" in before
-            raise
+    assert "RemoteActorError: ('name_error'" in before
-
+    assert "RemoteActorError: ('spawn_error'" in before
-        # in ci seems like this can sometimes just result
+    assert "RemoteActorError: ('name_error_1'" in before
-        # in full tree death?
+    assert 'bdb.BdbQuit' in before
-        print('tree died?')
-
-    else:
-        before = str(child.before.decode())
-        assert_before(child, [
-            # debugger attaches to root
-            "Attaching to pdb in crashed actor: ('root'",
-
-            # expect a multierror with exceptions for each sub-actor
-            "RemoteActorError: ('breakpoint_forever'",
-            "RemoteActorError: ('name_error'",
-            "RemoteActorError: ('spawn_error'",
-            "RemoteActorError: ('name_error_1'",
-            'bdb.BdbQuit',
-        ])
 
     if ctlc:
         do_ctlc(child)
 
     # process should exit
     child.sendline('c')
-
+    child.expect(pexpect.EOF)
-    try:
-        child.expect(pexpect.EOF)
-    except TIMEOUT:
-        child.expect(r"\(Pdb\+\+\)")
-
     # repeat of previous multierror for final output
-    assert_before(child, [
+    before = str(child.before.decode())
-        "RemoteActorError: ('breakpoint_forever'",
+    assert "RemoteActorError: ('breakpoint_forever'" in before
-        "RemoteActorError: ('name_error'",
+    assert "RemoteActorError: ('name_error'" in before
-        "RemoteActorError: ('spawn_error'",
+    assert "RemoteActorError: ('spawn_error'" in before
-        "RemoteActorError: ('name_error_1'",
+    assert "RemoteActorError: ('name_error_1'" in before
-        'bdb.BdbQuit',
+    assert 'bdb.BdbQuit' in before
-    ])
 
 
 def test_multi_daemon_subactors(
@@ -570,7 +544,7 @@ def test_multi_daemon_subactors(
     # now the root actor won't clobber the bp_forever child
     # during it's first access to the debug lock, but will instead
     # wait for the lock to release, by the edge triggered
-    # ``_debug.Lock.no_remote_has_tty`` event before sending cancel messages
+    # ``_debug._no_remote_has_tty`` event before sending cancel messages
     # (via portals) to its underlings B)
 
     # at some point here there should have been some warning msg from
@@ -603,7 +577,7 @@ def test_multi_daemon_subactors(
         child.sendline('c')
         child.expect(pexpect.EOF)
 
-    except TIMEOUT:
+    except pexpect.exceptions.TIMEOUT:
         # Failed to exit using continue..?
         child.sendline('q')
         child.expect(pexpect.EOF)
@@ -633,45 +607,32 @@ def test_multi_subactors_root_errors(
     # continue again to catch 2nd name error from
     # actor 'name_error_1' (which is 2nd depth).
     child.sendline('c')
-    try:
+    child.expect(r"\(Pdb\+\+\)")
-        child.expect(r"\(Pdb\+\+\)")
+    before = str(child.before.decode())
-    except TIMEOUT:
+    assert "Attaching to pdb in crashed actor: ('name_error_1'" in before
-        child.sendline('')
+    assert "NameError" in before
-
-    # XXX: lol honestly no idea why CI is cuck but
-    # seems like this likely falls into our unhandled nested
-    # case and isn't working in that env due to raciness..
-    from conftest import _ci_env
-    if not ctlc and _ci_env:
-        name = 'name_error' if ctlc else 'name_error_1'
-        assert_before(child, [
-            f"Attaching to pdb in crashed actor: ('{name}'",
-            "NameError",
-        ])
 
     if ctlc:
         do_ctlc(child)
 
     child.sendline('c')
     child.expect(r"\(Pdb\+\+\)")
-    assert_before(child, [
+    before = str(child.before.decode())
-        "Attaching to pdb in crashed actor: ('spawn_error'",
+    assert "Attaching to pdb in crashed actor: ('spawn_error'" in before
-        # boxed error from previous step
+    # boxed error from previous step
-        "RemoteActorError: ('name_error_1'",
+    assert "RemoteActorError: ('name_error_1'" in before
-        "NameError",
+    assert "NameError" in before
-    ])
 
     if ctlc:
         do_ctlc(child)
 
     child.sendline('c')
     child.expect(r"\(Pdb\+\+\)")
-    assert_before(child, [
+    before = str(child.before.decode())
-        "Attaching to pdb in crashed actor: ('root'",
+    assert "Attaching to pdb in crashed actor: ('root'" in before
-        # boxed error from previous step
+    # boxed error from first level failure
-        "RemoteActorError: ('name_error'",
+    assert "RemoteActorError: ('name_error'" in before
-        "NameError",
+    assert "NameError" in before
-    ])
 
     # warnings assert we probably don't need
     # assert "Cancelling nursery in ('spawn_error'," in before
@@ -715,7 +676,7 @@ def test_multi_nested_subactors_error_through_nurseries(
             child.sendline('c')
             time.sleep(0.1)
 
-        except EOF:
+        except pexpect.exceptions.EOF:
 
             # race conditions on how fast the continue is sent?
             print(f"Failed early on {i}?")
@@ -761,8 +722,8 @@ def test_root_nursery_cancels_before_child_releases_tty_lock(
             child.expect(r"\(Pdb\+\+\)")
 
         except (
-            EOF,
+            pexpect.exceptions.EOF,
-            TIMEOUT,
+            pexpect.exceptions.TIMEOUT,
         ):
             # races all over..
 
@@ -783,11 +744,11 @@ def test_root_nursery_cancels_before_child_releases_tty_lock(
         child.sendline('c')
         time.sleep(0.1)
 
-    for i in range(3):
+    for i in range(10):
         try:
             child.expect(pexpect.EOF)
             break
-        except TIMEOUT:
+        except pexpect.exceptions.TIMEOUT:
             child.sendline('c')
             time.sleep(0.1)
             print('child was able to grab tty lock again?')

tractor/_actor.py

@@ -967,7 +967,7 @@ class Actor:
                             # don't start entire actor runtime
                             # cancellation if this actor is in debug
                             # mode
-                            pdb_complete = _debug.Lock.local_pdb_complete
+                            pdb_complete = _debug._local_pdb_complete
                             if pdb_complete:
                                 await pdb_complete.wait()
 
@@ -1413,7 +1413,7 @@ class Actor:
 
             # kill any debugger request task to avoid deadlock
             # with the root actor in this tree
-            dbcs = _debug.Lock._debugger_request_cs
+            dbcs = _debug._debugger_request_cs
             if dbcs is not None:
                 log.cancel("Cancelling active debugger request")
                 dbcs.cancel()

tractor/_debug.py

@@ -60,81 +60,26 @@ log = get_logger(__name__)
 __all__ = ['breakpoint', 'post_mortem']
 
 
-class Lock:
+# TODO: wrap all these in a static global class: ``DebugLock`` maybe?
-    '''
-    Actor global debug lock state.
 
-    Mostly to avoid a lot of ``global`` declarations for now XD.
+# placeholder for function to set a ``trio.Event`` on debugger exit
+_pdb_release_hook: Optional[Callable] = None
 
-    '''
+# actor-wide variable pointing to current task name using debugger
-    # placeholder for function to set a ``trio.Event`` on debugger exit
+_local_task_in_debug: Optional[str] = None
-    pdb_release_hook: Optional[Callable] = None
 
-    # actor-wide variable pointing to current task name using debugger
+# actor tree-wide actor uid that supposedly has the tty lock
-    local_task_in_debug: Optional[str] = None
+_global_actor_in_debug: Optional[Tuple[str, str]] = None
 
-    # actor tree-wide actor uid that supposedly has the tty lock
+# lock in root actor preventing multi-access to local tty
-    global_actor_in_debug: Optional[Tuple[str, str]] = None
+_debug_lock: trio.StrictFIFOLock = trio.StrictFIFOLock()
+_local_pdb_complete: Optional[trio.Event] = None
+_no_remote_has_tty: Optional[trio.Event] = None
 
-    local_pdb_complete: Optional[trio.Event] = None
+# XXX: set by the current task waiting on the root tty lock
-    no_remote_has_tty: Optional[trio.Event] = None
+# and must be cancelled if this actor is cancelled via message
-
+# otherwise deadlocks with the parent actor may ensure
-    # lock in root actor preventing multi-access to local tty
+_debugger_request_cs: Optional[trio.CancelScope] = None
-    _debug_lock: trio.StrictFIFOLock = trio.StrictFIFOLock()
-
-    # XXX: set by the current task waiting on the root tty lock
-    # and must be cancelled if this actor is cancelled via message
-    # otherwise deadlocks with the parent actor may ensure
-    _debugger_request_cs: Optional[trio.CancelScope] = None
-
-    _orig_sigint_handler: Optional[Callable] = None
-
-    @classmethod
-    def shield_sigint(cls):
-        cls._orig_sigint_handler = signal.signal(
-                signal.SIGINT,
-                shield_sigint,
-            )
-
-    @classmethod
-    def unshield_sigint(cls):
-        if cls._orig_sigint_handler is not None:
-            # restore original sigint handler
-            signal.signal(
-                signal.SIGINT,
-                cls._orig_sigint_handler
-            )
-
-        cls._orig_sigint_handler = None
-
-    @classmethod
-    def maybe_release(cls):
-        cls.local_task_in_debug = None
-        if cls.pdb_release_hook:
-            cls.pdb_release_hook()
-
-    @classmethod
-    def root_release(cls):
-        try:
-            cls._debug_lock.release()
-        except RuntimeError:
-            # uhhh makes no sense but been seeing the non-owner
-            # release error even though this is definitely the task
-            # that locked?
-            owner = cls._debug_lock.statistics().owner
-            if owner:
-                raise
-
-        cls.global_actor_in_debug = None
-        cls.local_task_in_debug = None
-
-        try:
-            # sometimes the ``trio`` might already be terminated in
-            # which case this call will raise.
-            cls.local_pdb_complete.set()
-        finally:
-            # restore original sigint handler
-            cls.unshield_sigint()
 
 
 class TractorConfig(pdbpp.DefaultConfig):
@@ -163,13 +108,13 @@ class MultiActorPdb(pdbpp.Pdb):
         try:
             super().set_continue()
         finally:
-            Lock.maybe_release()
+            maybe_release()
 
     def set_quit(self):
         try:
             super().set_quit()
         finally:
-            Lock.maybe_release()
+            maybe_release()
 
 
 # TODO: will be needed whenever we get to true remote debugging.
@@ -208,6 +153,14 @@ class MultiActorPdb(pdbpp.Pdb):
 #                 log.info("Closing stdin hijack")
 #                 break
 
+# TODO: make this method on a global lock type!
+def maybe_release():
+    global _local_task_in_debug, _pdb_release_hook
+    _local_task_in_debug = None
+    if _pdb_release_hook:
+        _pdb_release_hook()
+
+
 @acm
 async def _acquire_debug_lock(
     uid: Tuple[str, str]
@@ -222,6 +175,8 @@ async def _acquire_debug_lock(
     to the ``pdb`` repl.
 
     '''
+    global _debug_lock, _global_actor_in_debug, _no_remote_has_tty
+
     task_name = trio.lowlevel.current_task().name
 
     log.runtime(
@@ -235,15 +190,15 @@ async def _acquire_debug_lock(
             f"entering lock checkpoint, remote task: {task_name}:{uid}"
         )
         we_acquired = True
-        await Lock._debug_lock.acquire()
+        await _debug_lock.acquire()
 
-        if Lock.no_remote_has_tty is None:
+        if _no_remote_has_tty is None:
             # mark the tty lock as being in use so that the runtime
             # can try to avoid clobbering any connection from a child
             # that's currently relying on it.
-            Lock.no_remote_has_tty = trio.Event()
+            _no_remote_has_tty = trio.Event()
 
-        Lock.global_actor_in_debug = uid
+        _global_actor_in_debug = uid
         log.runtime(f"TTY lock acquired, remote task: {task_name}:{uid}")
 
         # NOTE: critical section: this yield is unshielded!
@@ -256,32 +211,32 @@ async def _acquire_debug_lock(
         # surrounding caller side context should cancel normally
         # relaying back to the caller.
 
-        yield Lock._debug_lock
+        yield _debug_lock
 
     finally:
-        # if Lock.global_actor_in_debug == uid:
+        # if _global_actor_in_debug == uid:
 
         if (
             we_acquired
-            and Lock._debug_lock.locked()
+            and _debug_lock.locked()
         ):
-            Lock._debug_lock.release()
+            _debug_lock.release()
 
         # IFF there are no more requesting tasks queued up fire, the
         # "tty-unlocked" event thereby alerting any monitors of the lock that
         # we are now back in the "tty unlocked" state. This is basically
         # and edge triggered signal around an empty queue of sub-actor
         # tasks that may have tried to acquire the lock.
-        stats = Lock._debug_lock.statistics()
+        stats = _debug_lock.statistics()
         if (
             not stats.owner
         ):
             log.runtime(f"No more tasks waiting on tty lock! says {uid}")
-            if Lock.no_remote_has_tty is not None:
+            if _no_remote_has_tty is not None:
-                Lock.no_remote_has_tty.set()
+                _no_remote_has_tty.set()
-                Lock.no_remote_has_tty = None
+                _no_remote_has_tty = None
 
-        Lock.global_actor_in_debug = None
+        _global_actor_in_debug = None
 
         log.runtime(
             f"TTY lock released, remote task: {task_name}:{uid}"
@@ -316,8 +271,11 @@ async def _hijack_stdin_for_child(
     )
 
     log.debug(f"Actor {subactor_uid} is WAITING on stdin hijack lock")
-    Lock.shield_sigint()
 
+    orig_handler = signal.signal(
+        signal.SIGINT,
+        shield_sigint,
+    )
     try:
         with (
             trio.CancelScope(shield=True),
@@ -369,7 +327,10 @@ async def _hijack_stdin_for_child(
         return "pdb_unlock_complete"
 
     finally:
-        Lock.unshield_sigint()
+        signal.signal(
+            signal.SIGINT,
+            orig_handler
+        )
 
 
 async def wait_for_parent_stdin_hijack(
@@ -387,8 +348,10 @@ async def wait_for_parent_stdin_hijack(
     debug (see below inside ``maybe_wait_for_debugger()``).
 
     '''
+    global _debugger_request_cs
+
     with trio.CancelScope(shield=True) as cs:
-        Lock._debugger_request_cs = cs
+        _debugger_request_cs = cs
 
         try:
             async with get_root() as portal:
@@ -408,9 +371,9 @@ async def wait_for_parent_stdin_hijack(
                         # unblock local caller
 
                         try:
-                            assert Lock.local_pdb_complete
+                            assert _local_pdb_complete
                             task_status.started(cs)
-                            await Lock.local_pdb_complete.wait()
+                            await _local_pdb_complete.wait()
 
                         finally:
                             # TODO: shielding currently can cause hangs...
@@ -427,7 +390,8 @@ async def wait_for_parent_stdin_hijack(
 
         finally:
             log.pdb(f"Exiting debugger for actor {actor_uid}")
-            Lock.local_task_in_debug = None
+            global _local_task_in_debug
+            _local_task_in_debug = None
             log.pdb(f"Child {actor_uid} released parent stdio lock")
 
 
@@ -435,8 +399,10 @@ def mk_mpdb() -> tuple[MultiActorPdb, Callable]:
 
     pdb = MultiActorPdb()
     # signal.signal = pdbpp.hideframe(signal.signal)
-
+    orig_handler = signal.signal(
-    Lock.shield_sigint()
+        signal.SIGINT,
+        partial(shield_sigint, pdb_obj=pdb),
+    )
 
     # XXX: These are the important flags mentioned in
     # https://github.com/python-trio/trio/issues/1155
@@ -444,7 +410,15 @@ def mk_mpdb() -> tuple[MultiActorPdb, Callable]:
     pdb.allow_kbdint = True
     pdb.nosigint = True
 
-    return pdb, Lock.unshield_sigint
+    # TODO: add this as method on our pdb obj?
+    def undo_sigint():
+        # restore original sigint handler
+        signal.signal(
+            signal.SIGINT,
+            orig_handler
+        )
+
+    return pdb, undo_sigint
 
 
 async def _breakpoint(
@@ -466,6 +440,9 @@ async def _breakpoint(
     actor = tractor.current_actor()
     task_name = trio.lowlevel.current_task().name
 
+    global _local_pdb_complete, _pdb_release_hook
+    global _local_task_in_debug, _global_actor_in_debug
+
     # TODO: is it possible to debug a trio.Cancelled except block?
     # right now it seems like we can kinda do with by shielding
     # around ``tractor.breakpoint()`` but not if we move the shielded
@@ -473,14 +450,14 @@ async def _breakpoint(
     # with trio.CancelScope(shield=shield):
     #     await trio.lowlevel.checkpoint()
 
-    if not Lock.local_pdb_complete or Lock.local_pdb_complete.is_set():
+    if not _local_pdb_complete or _local_pdb_complete.is_set():
-        Lock.local_pdb_complete = trio.Event()
+        _local_pdb_complete = trio.Event()
 
     # TODO: need a more robust check for the "root" actor
     if actor._parent_chan and not is_root_process():
 
-        if Lock.local_task_in_debug:
+        if _local_task_in_debug:
-            if Lock.local_task_in_debug == task_name:
+            if _local_task_in_debug == task_name:
                 # this task already has the lock and is
                 # likely recurrently entering a breakpoint
                 return
@@ -490,18 +467,18 @@ async def _breakpoint(
             # support for recursive entries to `tractor.breakpoint()`
             log.warning(f"{actor.uid} already has a debug lock, waiting...")
 
-            await Lock.local_pdb_complete.wait()
+            await _local_pdb_complete.wait()
             await trio.sleep(0.1)
 
         # mark local actor as "in debug mode" to avoid recurrent
         # entries/requests to the root process
-        Lock.local_task_in_debug = task_name
+        _local_task_in_debug = task_name
 
         def child_release():
             try:
                 # sometimes the ``trio`` might already be termianated in
                 # which case this call will raise.
-                Lock.local_pdb_complete.set()
+                _local_pdb_complete.set()
             finally:
                 # restore original sigint handler
                 undo_sigint()
@@ -509,7 +486,7 @@ async def _breakpoint(
                 # _local_task_in_debug = None
 
         # assign unlock callback for debugger teardown hooks
-        Lock.pdb_release_hook = child_release
+        _pdb_release_hook = child_release
 
         # this **must** be awaited by the caller and is done using the
         # root nursery so that the debugger can continue to run without
@@ -526,39 +503,66 @@ async def _breakpoint(
                     actor.uid,
                 )
         except RuntimeError:
-            Lock.pdb_release_hook()
+            _pdb_release_hook()
             raise
 
     elif is_root_process():
 
         # we also wait in the root-parent for any child that
         # may have the tty locked prior
+        global _debug_lock
+
         # TODO: wait, what about multiple root tasks acquiring it though?
         # root process (us) already has it; ignore
-        if Lock.global_actor_in_debug == actor.uid:
+        if _global_actor_in_debug == actor.uid:
             return
 
         # XXX: since we need to enter pdb synchronously below,
         # we have to release the lock manually from pdb completion
         # callbacks. Can't think of a nicer way then this atm.
-        if Lock._debug_lock.locked():
+        if _debug_lock.locked():
             log.warning(
                 'Root actor attempting to shield-acquire active tty lock'
-                f' owned by {Lock.global_actor_in_debug}')
+                f' owned by {_global_actor_in_debug}')
 
             # must shield here to avoid hitting a ``Cancelled`` and
             # a child getting stuck bc we clobbered the tty
             with trio.CancelScope(shield=True):
-                await Lock._debug_lock.acquire()
+                await _debug_lock.acquire()
         else:
             # may be cancelled
-            await Lock._debug_lock.acquire()
+            await _debug_lock.acquire()
 
-        Lock.global_actor_in_debug = actor.uid
+        _global_actor_in_debug = actor.uid
-        Lock.local_task_in_debug = task_name
+        _local_task_in_debug = task_name
 
         # the lock must be released on pdb completion
-        Lock.pdb_release_hook = Lock.root_release
+        def root_release():
+            global _local_pdb_complete, _debug_lock
+            global _global_actor_in_debug, _local_task_in_debug
+
+            try:
+                _debug_lock.release()
+            except RuntimeError:
+                # uhhh makes no sense but been seeing the non-owner
+                # release error even though this is definitely the task
+                # that locked?
+                owner = _debug_lock.statistics().owner
+                if owner:
+                    raise
+
+            _global_actor_in_debug = None
+            _local_task_in_debug = None
+
+            try:
+                # sometimes the ``trio`` might already be termianated in
+                # which case this call will raise.
+                _local_pdb_complete.set()
+            finally:
+                # restore original sigint handler
+                undo_sigint()
+
+        _pdb_release_hook = root_release
 
     try:
         # block here one (at the appropriate frame *up*) where
@@ -567,7 +571,7 @@ async def _breakpoint(
         debug_func(actor, pdb)
 
     except bdb.BdbQuit:
-        Lock.maybe_release()
+        maybe_release()
         raise
 
     # XXX: apparently we can't do this without showing this frame
@@ -603,7 +607,8 @@ def shield_sigint(
     '''
     __tracebackhide__ = True
 
-    uid_in_debug = Lock.global_actor_in_debug
+    global _local_task_in_debug, _global_actor_in_debug
+    uid_in_debug = _global_actor_in_debug
 
     actor = tractor.current_actor()
 
@@ -676,7 +681,7 @@ def shield_sigint(
             )
             return do_cancel()
 
-        task = Lock.local_task_in_debug
+        task = _local_task_in_debug
         if task:
             log.pdb(
                 f"Ignoring SIGINT while task in debug mode: `{task}`"
@@ -749,7 +754,8 @@ def _set_trace(
         pdb, undo_sigint = mk_mpdb()
 
         # we entered the global ``breakpoint()`` built-in from sync code?
-        Lock.local_task_in_debug = 'sync'
+        global _local_task_in_debug, _pdb_release_hook
+        _local_task_in_debug = 'sync'
 
     pdb.set_trace(frame=frame)
 
@@ -824,7 +830,7 @@ async def _maybe_enter_pm(err):
     ):
         log.debug("Actor crashed, entering debug mode")
         await post_mortem()
-        Lock.maybe_release()
+        maybe_release()
         return True
 
     else:
@@ -869,6 +875,8 @@ async def maybe_wait_for_debugger(
     if (
         is_root_process()
     ):
+        global _no_remote_has_tty, _global_actor_in_debug, _wait_all_tasks_lock
+
         # If we error in the root but the debugger is
         # engaged we don't want to prematurely kill (and
         # thus clobber access to) the local tty since it
@@ -880,8 +888,8 @@ async def maybe_wait_for_debugger(
 
         for _ in range(poll_steps):
 
-            if Lock.global_actor_in_debug:
+            if _global_actor_in_debug:
-                sub_in_debug = tuple(Lock.global_actor_in_debug)
+                sub_in_debug = tuple(_global_actor_in_debug)
                 # alive = tractor.current_actor().child_alive(sub_in_debug)
                 # if not alive:
                 #     break
@@ -897,7 +905,7 @@ async def maybe_wait_for_debugger(
                 # XXX: doesn't seem to work
                 # await trio.testing.wait_all_tasks_blocked(cushion=0)
 
-                debug_complete = Lock.no_remote_has_tty
+                debug_complete = _no_remote_has_tty
                 if (
                     (debug_complete and
                      not debug_complete.is_set())