Yahh, add `.devx` package to installed subpkgs..

If `stackscope` is importable and debug_mode is enabled then we by
default call and report `.devx.enable_stack_on_sig()` is set B)

This makes debugging unexpected (SIGINT ignoring) hangs a cinch!

docs/README.rst

@@ -3,8 +3,8 @@
 |gh_actions|
 |docs|
 
-``tractor`` is a `structured concurrent`_, multi-processing_ runtime
-built on trio_.
+``tractor`` is a `structured concurrent`_, (optionally
+distributed_) multi-processing_ runtime built on trio_.
 
 Fundamentally, ``tractor`` gives you parallelism via
 ``trio``-"*actors*": independent Python processes (aka
@@ -17,11 +17,20 @@ protocol" constructed on top of multiple Pythons each running a ``trio``
 scheduled runtime - a call to ``trio.run()``.
 
 We believe the system adheres to the `3 axioms`_ of an "`actor model`_"
-but likely *does not* look like what *you* probably think an "actor
-model" looks like, and that's *intentional*.
+but likely **does not** look like what **you** probably *think* an "actor
+model" looks like, and that's **intentional**.
 
-The first step to grok ``tractor`` is to get the basics of ``trio`` down.
-A great place to start is the `trio docs`_ and this `blog post`_.
+
+Where do i start!?
+------------------
+The first step to grok ``tractor`` is to get an intermediate
+knowledge of ``trio`` and **structured concurrency** B)
+
+Some great places to start are,
+- the seminal `blog post`_
+- obviously the `trio docs`_
+- wikipedia's nascent SC_ page
+- the fancy diagrams @ libdill-docs_
 
 
 Features
@@ -593,6 +602,7 @@ matrix seems too hip, we're also mostly all in the the `trio gitter
 channel`_!
 
 .. _structured concurrent: https://trio.discourse.group/t/concise-definition-of-structured-concurrency/228
+.. _distributed: https://en.wikipedia.org/wiki/Distributed_computing
 .. _multi-processing: https://en.wikipedia.org/wiki/Multiprocessing
 .. _trio: https://github.com/python-trio/trio
 .. _nurseries: https://vorpus.org/blog/notes-on-structured-concurrency-or-go-statement-considered-harmful/#nurseries-a-structured-replacement-for-go-statements
@@ -611,8 +621,9 @@ channel`_!
 .. _trio docs: https://trio.readthedocs.io/en/latest/
 .. _blog post: https://vorpus.org/blog/notes-on-structured-concurrency-or-go-statement-considered-harmful/
 .. _structured concurrency: https://en.wikipedia.org/wiki/Structured_concurrency
+.. _SC: https://en.wikipedia.org/wiki/Structured_concurrency
+.. _libdill-docs: https://sustrik.github.io/libdill/structured-concurrency.html
 .. _structured chadcurrency: https://en.wikipedia.org/wiki/Structured_concurrency
-.. _structured concurrency: https://en.wikipedia.org/wiki/Structured_concurrency
 .. _unrequirements: https://en.wikipedia.org/wiki/Actor_model#Direct_communication_and_asynchrony
 .. _async generators: https://www.python.org/dev/peps/pep-0525/
 .. _trio-parallel: https://github.com/richardsheridan/trio-parallel

examples/debugging/asyncio_bp.py

@@ -0,0 +1,117 @@
+import asyncio
+
+import trio
+import tractor
+from tractor import to_asyncio
+
+
+async def aio_sleep_forever():
+    await asyncio.sleep(float('inf'))
+
+
+async def bp_then_error(
+    to_trio: trio.MemorySendChannel,
+    from_trio: asyncio.Queue,
+
+    raise_after_bp: bool = True,
+
+) -> None:
+
+    # sync with ``trio``-side (caller) task
+    to_trio.send_nowait('start')
+
+    # NOTE: what happens here inside the hook needs some refinement..
+    # => seems like it's still `._debug._set_trace()` but
+    #    we set `Lock.local_task_in_debug = 'sync'`, we probably want
+    #    some further, at least, meta-data about the task/actoq in debug
+    #    in terms of making it clear it's asyncio mucking about.
+    breakpoint()
+
+    # short checkpoint / delay
+    await asyncio.sleep(0.5)
+
+    if raise_after_bp:
+        raise ValueError('blah')
+
+    # TODO: test case with this so that it gets cancelled?
+    else:
+        # XXX NOTE: this is required in order to get the SIGINT-ignored
+        # hang case documented in the module script section!
+        await aio_sleep_forever()
+
+
+@tractor.context
+async def trio_ctx(
+    ctx: tractor.Context,
+    bp_before_started: bool = False,
+):
+
+    # this will block until the ``asyncio`` task sends a "first"
+    # message, see first line in above func.
+    async with (
+
+        to_asyncio.open_channel_from(
+            bp_then_error,
+            raise_after_bp=not bp_before_started,
+        ) as (first, chan),
+
+        trio.open_nursery() as n,
+    ):
+
+        assert first == 'start'
+
+        if bp_before_started:
+            await tractor.breakpoint()
+
+        await ctx.started(first)
+
+        n.start_soon(
+            to_asyncio.run_task,
+            aio_sleep_forever,
+        )
+        await trio.sleep_forever()
+
+
+async def main(
+    bps_all_over: bool = False,
+
+) -> None:
+
+    async with tractor.open_nursery() as n:
+
+        p = await n.start_actor(
+            'aio_daemon',
+            enable_modules=[__name__],
+            infect_asyncio=True,
+            debug_mode=True,
+            loglevel='cancel',
+        )
+
+        async with p.open_context(
+            trio_ctx,
+            bp_before_started=bps_all_over,
+        ) as (ctx, first):
+
+            assert first == 'start'
+
+            if bps_all_over:
+                await tractor.breakpoint()
+
+            # await trio.sleep_forever()
+            await ctx.cancel()
+            assert 0
+
+        # TODO: case where we cancel from trio-side while asyncio task
+        # has debugger lock?
+        # await p.cancel_actor()
+
+
+if __name__ == '__main__':
+
+    # works fine B)
+    trio.run(main)
+
+    # will hang and ignores SIGINT !!
+    # NOTE: you'll need to send a SIGQUIT (via ctl-\) to kill it
+    # manually..
+    # trio.run(main, True)

setup.py

@@ -26,7 +26,7 @@ with open('docs/README.rst', encoding='utf-8') as f:
 setup(
     name="tractor",
     version='0.1.0a6dev0',  # alpha zone
-    description='structured concurrrent `trio`-"actors"',
+    description='structured concurrent `trio`-"actors"',
     long_description=readme,
     license='AGPLv3',
     author='Tyler Goodlet',
@@ -39,6 +39,7 @@ setup(
         'tractor.experimental',  # wacky ideas
         'tractor.trionics',  # trio extensions
         'tractor.msg',  # lowlevel data types
+        'tractor.devx',  # "dev-experience"
     ],
     install_requires=[
 
@@ -52,6 +53,7 @@ setup(
         # 'exceptiongroup',  # in stdlib as of 3.11!
 
         # tooling
+        'stackscope',
         'tricycle',
         'trio_typing',
         'colorlog',
@@ -63,16 +65,15 @@ setup(
         # debug mode REPL
         'pdbp',
 
+        # TODO: distributed transport using
+        # linux kernel networking
+        # 'pyroute2',
+
         # pip ref docs on these specs:
         # https://pip.pypa.io/en/stable/reference/requirement-specifiers/#examples
         # and pep:
         # https://peps.python.org/pep-0440/#version-specifiers
 
-        # windows deps workaround for ``pdbpp``
-        # https://github.com/pdbpp/pdbpp/issues/498
-        # https://github.com/pdbpp/fancycompleter/issues/37
-        'pyreadline3 ; platform_system == "Windows"',
-
     ],
     tests_require=['pytest'],
     python_requires=">=3.10",

tests/test_debugger.py

@@ -10,6 +10,7 @@ TODO:
     - wonder if any of it'll work on OS X?
 
 """
+from functools import partial
 import itertools
 from typing import Optional
 import platform
@@ -26,6 +27,10 @@ from pexpect.exceptions import (
 from tractor._testing import (
     examples_dir,
 )
+from tractor.devx._debug import (
+    _pause_msg,
+    _crash_msg,
+)
 from conftest import (
     _ci_env,
 )
@@ -123,20 +128,52 @@ def expect(
         raise
 
 
+def in_prompt_msg(
+    prompt: str,
+    parts: list[str],
+
+    pause_on_false: bool = False,
+    print_prompt_on_false: bool = True,
+
+) -> bool:
+    '''
+    Predicate check if (the prompt's) std-streams output has all
+    `str`-parts in it.
+
+    Can be used in test asserts for bulk matching expected
+    log/REPL output for a given `pdb` interact point.
+
+    '''
+    for part in parts:
+        if part not in prompt:
+
+            if pause_on_false:
+                import pdbp
+                pdbp.set_trace()
+
+            if print_prompt_on_false:
+                print(prompt)
+
+            return False
+
+    return True
+
 def assert_before(
     child,
     patts: list[str],
 
+    **kwargs,
+
 ) -> None:
 
-    before = str(child.before.decode())
+    # as in before the prompt end
+    before: str = str(child.before.decode())
+    assert in_prompt_msg(
+        prompt=before,
+        parts=patts,
 
-    for patt in patts:
-        try:
-            assert patt in before
-        except AssertionError:
-            print(before)
-            raise
+        **kwargs
+    )
 
 
 @pytest.fixture(
@@ -195,7 +232,10 @@ def test_root_actor_error(spawn, user_in_out):
     before = str(child.before.decode())
 
     # make sure expected logging and error arrives
-    assert "Attaching to pdb in crashed actor: ('root'" in before
+    assert in_prompt_msg(
+        before,
+        [_crash_msg, "('root'"]
+    )
     assert 'AssertionError' in before
 
     # send user command
@@ -332,7 +372,10 @@ def test_subactor_error(
     child.expect(PROMPT)
 
     before = str(child.before.decode())
-    assert "Attaching to pdb in crashed actor: ('name_error'" in before
+    assert in_prompt_msg(
+        before,
+        [_crash_msg, "('name_error'"]
+    )
 
     if do_next:
         child.sendline('n')
@@ -353,9 +396,15 @@ def test_subactor_error(
     before = str(child.before.decode())
 
     # root actor gets debugger engaged
-    assert "Attaching to pdb in crashed actor: ('root'" in before
+    assert in_prompt_msg(
+        before,
+        [_crash_msg, "('root'"]
+    )
     # error is a remote error propagated from the subactor
-    assert "RemoteActorError: ('name_error'" in before
+    assert in_prompt_msg(
+        before,
+        [_crash_msg, "('name_error'"]
+    )
 
     # another round
     if ctlc:
@@ -380,7 +429,10 @@ def test_subactor_breakpoint(
     child.expect(PROMPT)
 
     before = str(child.before.decode())
-    assert "Attaching pdb to actor: ('breakpoint_forever'" in before
+    assert in_prompt_msg(
+        before,
+        [_pause_msg, "('breakpoint_forever'"]
+    )
 
     # do some "next" commands to demonstrate recurrent breakpoint
     # entries
@@ -396,7 +448,10 @@ def test_subactor_breakpoint(
         child.sendline('continue')
         child.expect(PROMPT)
         before = str(child.before.decode())
-        assert "Attaching pdb to actor: ('breakpoint_forever'" in before
+        assert in_prompt_msg(
+            before,
+            [_pause_msg, "('breakpoint_forever'"]
+        )
 
         if ctlc:
             do_ctlc(child)
@@ -441,7 +496,10 @@ def test_multi_subactors(
     child.expect(PROMPT)
 
     before = str(child.before.decode())
-    assert "Attaching pdb to actor: ('breakpoint_forever'" in before
+    assert in_prompt_msg(
+        before,
+        [_pause_msg, "('breakpoint_forever'"]
+    )
 
     if ctlc:
         do_ctlc(child)
@@ -461,7 +519,10 @@ def test_multi_subactors(
     # first name_error failure
     child.expect(PROMPT)
     before = str(child.before.decode())
-    assert "Attaching to pdb in crashed actor: ('name_error'" in before
+    assert in_prompt_msg(
+        before,
+        [_crash_msg, "('name_error'"]
+    )
     assert "NameError" in before
 
     if ctlc:
@@ -487,7 +548,10 @@ def test_multi_subactors(
     child.sendline('c')
     child.expect(PROMPT)
     before = str(child.before.decode())
-    assert "Attaching pdb to actor: ('breakpoint_forever'" in before
+    assert in_prompt_msg(
+        before,
+        [_pause_msg, "('breakpoint_forever'"]
+    )
 
     if ctlc:
         do_ctlc(child)
@@ -527,9 +591,12 @@ def test_multi_subactors(
     child.expect(PROMPT)
     before = str(child.before.decode())
 
-    assert_before(child, [
+    assert_before(
+        child, [
             # debugger attaches to root
-        "Attaching to pdb in crashed actor: ('root'",
+            # "Attaching to pdb in crashed actor: ('root'",
+            _crash_msg,
+            "('root'",
 
             # expect a multierror with exceptions for each sub-actor
             "RemoteActorError: ('breakpoint_forever'",
@@ -537,7 +604,8 @@ def test_multi_subactors(
             "RemoteActorError: ('spawn_error'",
             "RemoteActorError: ('name_error_1'",
             'bdb.BdbQuit',
-    ])
+        ]
+    )
 
     if ctlc:
         do_ctlc(child)
@@ -574,15 +642,22 @@ def test_multi_daemon_subactors(
     # the root's tty lock first so anticipate either crash
     # message on the first entry.
 
-    bp_forever_msg = "Attaching pdb to actor: ('bp_forever'"
+    bp_forev_parts = [_pause_msg, "('bp_forever'"]
+    bp_forev_in_msg = partial(
+        in_prompt_msg,
+        parts=bp_forev_parts,
+    )
+
     name_error_msg = "NameError: name 'doggypants' is not defined"
+    name_error_parts = [name_error_msg]
 
     before = str(child.before.decode())
-    if bp_forever_msg in before:
-        next_msg = name_error_msg
+
+    if bp_forev_in_msg(prompt=before):
+        next_parts = name_error_parts
 
     elif name_error_msg in before:
-        next_msg = bp_forever_msg
+        next_parts = bp_forev_parts
 
     else:
         raise ValueError("Neither log msg was found !?")
@@ -599,7 +674,10 @@ def test_multi_daemon_subactors(
 
     child.sendline('c')
     child.expect(PROMPT)
-    assert_before(child, [next_msg])
+    assert_before(
+        child,
+        next_parts,
+    )
 
     # XXX: hooray the root clobbering the child here was fixed!
     # IMO, this demonstrates the true power of SC system design.
@@ -623,9 +701,15 @@ def test_multi_daemon_subactors(
     child.expect(PROMPT)
 
     try:
-        assert_before(child, [bp_forever_msg])
+        assert_before(
+            child,
+            bp_forev_parts,
+        )
     except AssertionError:
-        assert_before(child, [name_error_msg])
+        assert_before(
+            child,
+            name_error_parts,
+        )
 
     else:
         if ctlc:
@@ -637,7 +721,10 @@ def test_multi_daemon_subactors(
 
         child.sendline('c')
         child.expect(PROMPT)
-        assert_before(child, [name_error_msg])
+        assert_before(
+            child,
+            name_error_parts,
+        )
 
     # wait for final error in root
     # where it crashs with boxed error
@@ -647,7 +734,7 @@ def test_multi_daemon_subactors(
             child.expect(PROMPT)
             assert_before(
                 child,
-                [bp_forever_msg]
+                bp_forev_parts
             )
         except AssertionError:
             break
@@ -656,7 +743,9 @@ def test_multi_daemon_subactors(
         child,
         [
             # boxed error raised in root task
-            "Attaching to pdb in crashed actor: ('root'",
+            # "Attaching to pdb in crashed actor: ('root'",
+            _crash_msg,
+            "('root'",
             "_exceptions.RemoteActorError: ('name_error'",
         ]
     )
@@ -770,7 +859,7 @@ def test_multi_nested_subactors_error_through_nurseries(
 
     child = spawn('multi_nested_subactors_error_up_through_nurseries')
 
-    timed_out_early: bool = False
+    # timed_out_early: bool = False
 
     for send_char in itertools.cycle(['c', 'q']):
         try:
@@ -871,11 +960,14 @@ def test_root_nursery_cancels_before_child_releases_tty_lock(
 
     if not timed_out_early:
         before = str(child.before.decode())
-        assert_before(child, [
+        assert_before(
+            child,
+            [
                 "tractor._exceptions.RemoteActorError: ('spawner0'",
                 "tractor._exceptions.RemoteActorError: ('name_error'",
                 "NameError: name 'doggypants' is not defined",
-        ])
+            ],
+        )
 
 
 def test_root_cancels_child_context_during_startup(
@@ -909,8 +1001,10 @@ def test_different_debug_mode_per_actor(
 
     # only one actor should enter the debugger
     before = str(child.before.decode())
-    assert "Attaching to pdb in crashed actor: ('debugged_boi'" in before
-    assert "RuntimeError" in before
+    assert in_prompt_msg(
+        before,
+        [_crash_msg, "('debugged_boi'", "RuntimeError"],
+    )
 
     if ctlc:
         do_ctlc(child)

tractor/__init__.py

@@ -21,7 +21,6 @@ tractor: structured concurrent ``trio``-"actors".
 from exceptiongroup import BaseExceptionGroup
 
 from ._clustering import open_actor_cluster
-from ._ipc import Channel
 from ._context import (
     Context,  # the type
     context,  # a func-decorator
@@ -46,8 +45,10 @@ from ._exceptions import (
     ModuleNotExposed,
     ContextCancelled,
 )
-from ._debug import (
+from .devx import (
     breakpoint,
+    pause,
+    pause_from_sync,
     post_mortem,
 )
 from . import msg
@@ -55,31 +56,35 @@ from ._root import (
     run_daemon,
     open_root_actor,
 )
+from ._ipc import Channel
 from ._portal import Portal
 from ._runtime import Actor
 
 
 __all__ = [
     'Actor',
+    'BaseExceptionGroup',
     'Channel',
     'Context',
     'ContextCancelled',
     'ModuleNotExposed',
     'MsgStream',
-    'BaseExceptionGroup',
     'Portal',
     'RemoteActorError',
     'breakpoint',
     'context',
     'current_actor',
     'find_actor',
+    'query_actor',
     'get_arbiter',
     'is_root_process',
     'msg',
     'open_actor_cluster',
     'open_nursery',
     'open_root_actor',
+    'pause',
     'post_mortem',
+    'pause_from_sync',
     'query_actor',
     'run_daemon',
     'stream',

tractor/_context.py

@@ -868,6 +868,9 @@ class Context:
 
         # TODO: maybe we should also call `._res_scope.cancel()` if it
         # exists to support cancelling any drain loop hangs?
+        # NOTE: this usage actually works here B)
+        # from .devx._debug import breakpoint
+        # await breakpoint()
 
     # TODO: add to `Channel`?
     @property

tractor/_root.py

@@ -38,7 +38,7 @@ from ._runtime import (
     # Arbiter as Registry,
     async_main,
 )
-from . import _debug
+from .devx import _debug
 from . import _spawn
 from . import _state
 from . import log
@@ -90,7 +90,7 @@ async def open_root_actor(
     # https://github.com/python-trio/trio/issues/1155#issuecomment-742964018
     builtin_bp_handler = sys.breakpointhook
     orig_bp_path: str | None = os.environ.get('PYTHONBREAKPOINT', None)
-    os.environ['PYTHONBREAKPOINT'] = 'tractor._debug._set_trace'
+    os.environ['PYTHONBREAKPOINT'] = 'tractor.devx._debug.pause_from_sync'
 
     # attempt to retreive ``trio``'s sigint handler and stash it
     # on our debugger lock state.
@@ -131,14 +131,20 @@ async def open_root_actor(
         )
     )
 
-    loglevel = (loglevel or log._default_loglevel).upper()
+    loglevel = (
+        loglevel
+        or log._default_loglevel
+    ).upper()
 
-    if debug_mode and _spawn._spawn_method == 'trio':
+    if (
+        debug_mode
+        and _spawn._spawn_method == 'trio'
+    ):
         _state._runtime_vars['_debug_mode'] = True
 
-        # expose internal debug module to every actor allowing
-        # for use of ``await tractor.breakpoint()``
-        enable_modules.append('tractor._debug')
+        # expose internal debug module to every actor allowing for
+        # use of ``await tractor.pause()``
+        enable_modules.append('tractor.devx._debug')
 
         # if debug mode get's enabled *at least* use that level of
         # logging for some informative console prompts.
@@ -156,7 +162,20 @@ async def open_root_actor(
             "Debug mode is only supported for the `trio` backend!"
         )
 
-    log.get_console_log(loglevel)
+    assert loglevel
+    _log = log.get_console_log(loglevel)
+    assert _log
+
+    # TODO: factor this into `.devx._stackscope`!!
+    if debug_mode:
+        try:
+            logger.info('Enabling `stackscope` traces on SIGUSR1')
+            from .devx import enable_stack_on_sig
+            enable_stack_on_sig()
+        except ImportError:
+            logger.warning(
+                '`stackscope` not installed for use in debug mode!'
+            )
 
     try:
         # make a temporary connection to see if an arbiter exists,
@@ -237,10 +256,10 @@ async def open_root_actor(
             ) as err:
 
                 entered = await _debug._maybe_enter_pm(err)
-
                 if (
                     not entered
-                    and not is_multi_cancelled(err)
+                    and
+                    not is_multi_cancelled(err)
                 ):
                     logger.exception('Root actor crashed:\n')
 

tractor/_runtime.py

@@ -78,7 +78,7 @@ from ._exceptions import (
     TransportClosed,
 )
 from ._discovery import get_arbiter
-from . import _debug
+from .devx import _debug
 from ._portal import Portal
 from . import _state
 from . import _mp_fixup_main
@@ -187,7 +187,7 @@ class Actor:
         self._parent_main_data = _mp_fixup_main._mp_figure_out_main()
 
         # always include debugging tools module
-        enable_modules.append('tractor._debug')
+        enable_modules.append('tractor.devx._debug')
 
         mods = {}
         for name in enable_modules:
@@ -632,7 +632,7 @@ class Actor:
                         and not db_cs.cancel_called
                         and uid == pdb_user_uid
                     ):
-                        log.warning(
+                        log.critical(
                             f'STALE DEBUG LOCK DETECTED FOR {uid}'
                         )
                         # TODO: figure out why this breaks tests..
@@ -1723,4 +1723,6 @@ class Arbiter(Actor):
 
     ) -> None:
         uid = (str(uid[0]), str(uid[1]))
-        self._registry.pop(uid)
+        entry: tuple = self._registry.pop(uid, None)
+        if entry is None:
+            log.warning(f'Request to de-register {uid} failed?')

tractor/_spawn.py

@@ -34,7 +34,7 @@ from typing import (
 import trio
 from trio import TaskStatus
 
-from ._debug import (
+from .devx._debug import (
     maybe_wait_for_debugger,
     acquire_debug_lock,
 )
@@ -551,13 +551,14 @@ async def trio_proc(
                         with trio.move_on_after(0.5):
                             await proc.wait()
 
-                log.pdb(
-                    'Delaying subproc reaper while debugger locked..'
-                )
                 await maybe_wait_for_debugger(
                     child_in_debug=_runtime_vars.get(
                         '_debug_mode', False
                     ),
+                    header_msg=(
+                        'Delaying subproc reaper while debugger locked..\n'
+                    ),
+
                     # TODO: need a diff value then default?
                     # poll_steps=9999999,
                 )

tractor/_supervise.py

@@ -31,7 +31,7 @@ import warnings
 
 import trio
 
-from ._debug import maybe_wait_for_debugger
+from .devx._debug import maybe_wait_for_debugger
 from ._state import current_actor, is_main_process
 from .log import get_logger, get_loglevel
 from ._runtime import Actor

tractor/devx/__init__.py

@@ -0,0 +1,37 @@
+# tractor: structured concurrent "actors".
+# Copyright 2018-eternity Tyler Goodlet.
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+"""
+Runtime "developer experience" utils and addons to aid our
+(advanced) users and core devs in building distributed applications
+and working with/on the actor runtime.
+
+"""
+from ._debug import (
+    maybe_wait_for_debugger as maybe_wait_for_debugger,
+    acquire_debug_lock as acquire_debug_lock,
+    breakpoint as breakpoint,
+    pause as pause,
+    pause_from_sync as pause_from_sync,
+    shield_sigint_handler as shield_sigint_handler,
+    MultiActorPdb as MultiActorPdb,
+    open_crash_handler as open_crash_handler,
+    maybe_open_crash_handler as maybe_open_crash_handler,
+    post_mortem as post_mortem,
+)
+from ._stackscope import (
+    enable_stack_on_sig as enable_stack_on_sig,
+)

tractor/devx/_stackscope.py

@@ -0,0 +1,84 @@
+# tractor: structured concurrent "actors".
+# Copyright eternity Tyler Goodlet.
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+'''
+The fundamental cross process SC abstraction: an inter-actor,
+cancel-scope linked task "context".
+
+A ``Context`` is very similar to the ``trio.Nursery.cancel_scope`` built
+into each ``trio.Nursery`` except it links the lifetimes of memory space
+disjoint, parallel executing tasks in separate actors.
+
+'''
+from signal import (
+    signal,
+    SIGUSR1,
+)
+
+import trio
+
+@trio.lowlevel.disable_ki_protection
+def dump_task_tree() -> None:
+    import stackscope
+    from tractor.log import get_console_log
+
+    tree_str: str = str(
+        stackscope.extract(
+            trio.lowlevel.current_root_task(),
+            recurse_child_tasks=True
+        )
+    )
+    log = get_console_log('cancel')
+    log.pdb(
+        f'Dumping `stackscope` tree:\n\n'
+        f'{tree_str}\n'
+    )
+    # import logging
+    # try:
+    #     with open("/dev/tty", "w") as tty:
+    #         tty.write(tree_str)
+    # except BaseException:
+    #     logging.getLogger(
+    #         "task_tree"
+    #     ).exception("Error printing task tree")
+
+
+def signal_handler(sig: int, frame: object) -> None:
+    import traceback
+    try:
+        trio.lowlevel.current_trio_token(
+        ).run_sync_soon(dump_task_tree)
+    except RuntimeError:
+        # not in async context -- print a normal traceback
+        traceback.print_stack()
+
+
+
+def enable_stack_on_sig(
+    sig: int = SIGUSR1
+) -> None:
+    '''
+    Enable `stackscope` tracing on reception of a signal; by
+    default this is SIGUSR1.
+
+    '''
+    signal(
+        sig,
+        signal_handler,
+    )
+    # NOTE: not the above can be triggered from
+    # a (xonsh) shell using:
+    # kill -SIGUSR1 @$(pgrep -f '<cmd>')

tractor/devx/cli.py

@@ -0,0 +1,129 @@
+# tractor: structured concurrent "actors".
+# Copyright 2018-eternity Tyler Goodlet.
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+"""
+CLI framework extensions for hacking on the actor runtime.
+
+Currently popular frameworks supported are:
+
+  - `typer` via the `@callback` API
+
+"""
+from __future__ import annotations
+from typing import (
+    Any,
+    Callable,
+)
+from typing_extensions import Annotated
+
+import typer
+
+
+_runtime_vars: dict[str, Any] = {}
+
+
+def load_runtime_vars(
+    ctx: typer.Context,
+    callback: Callable,
+    pdb: bool = False,  # --pdb
+    ll: Annotated[
+        str,
+        typer.Option(
+            '--loglevel',
+            '-l',
+            help='BigD logging level',
+        ),
+    ] = 'cancel',  # -l info
+):
+    '''
+    Maybe engage crash handling with `pdbp` when code inside
+    a `typer` CLI endpoint cmd raises.
+
+    To use this callback simply take your `app = typer.Typer()` instance
+    and decorate this function with it like so:
+
+    .. code:: python
+
+        from tractor.devx import cli
+
+        app = typer.Typer()
+
+        # manual decoration to hook into `click`'s context system!
+        cli.load_runtime_vars = app.callback(
+            invoke_without_command=True,
+        )
+
+    And then you can use the now augmented `click` CLI context as so,
+
+    .. code:: python
+
+        @app.command(
+            context_settings={
+                "allow_extra_args": True,
+                "ignore_unknown_options": True,
+            }
+        )
+        def my_cli_cmd(
+            ctx: typer.Context,
+        ):
+            rtvars: dict = ctx.runtime_vars
+            pdb: bool = rtvars['pdb']
+
+            with tractor.devx.cli.maybe_open_crash_handler(pdb=pdb):
+                trio.run(
+                    partial(
+                        my_tractor_main_task_func,
+                        debug_mode=pdb,
+                        loglevel=rtvars['ll'],
+                    )
+                )
+
+    which will enable log level and debug mode globally for the entire
+    `tractor` + `trio` runtime thereafter!
+
+    Bo
+
+    '''
+    global _runtime_vars
+    _runtime_vars |= {
+        'pdb': pdb,
+        'll': ll,
+    }
+
+    ctx.runtime_vars: dict[str, Any] = _runtime_vars
+    print(
+        f'`typer` sub-cmd: {ctx.invoked_subcommand}\n'
+        f'`tractor` runtime vars: {_runtime_vars}'
+    )
+
+    # XXX NOTE XXX: hackzone.. if no sub-cmd is specified (the
+    # default if the user just invokes `bigd`) then we simply
+    # invoke the sole `_bigd()` cmd passing in the "parent"
+    # typer.Context directly to that call since we're treating it
+    # as a "non sub-command" or wtv..
+    # TODO: ideally typer would have some kinda built-in way to get
+    # this behaviour without having to construct and manually
+    # invoke our own cmd..
+    if (
+        ctx.invoked_subcommand is None
+        or ctx.invoked_subcommand == callback.__name__
+    ):
+        cmd: typer.core.TyperCommand = typer.core.TyperCommand(
+            name='bigd',
+            callback=callback,
+        )
+        ctx.params = {'ctx': ctx}
+        cmd.invoke(ctx)

tractor/to_asyncio.py

@@ -28,7 +28,6 @@ from typing import (
     Callable,
     AsyncIterator,
     Awaitable,
-    Optional,
 )
 
 import trio
@@ -65,9 +64,9 @@ class LinkedTaskChannel(trio.abc.Channel):
     _trio_exited: bool = False
 
     # set after ``asyncio.create_task()``
-    _aio_task: Optional[asyncio.Task] = None
-    _aio_err: Optional[BaseException] = None
-    _broadcaster: Optional[BroadcastReceiver] = None
+    _aio_task: asyncio.Task | None = None
+    _aio_err: BaseException | None = None
+    _broadcaster: BroadcastReceiver | None = None
 
     async def aclose(self) -> None:
         await self._from_aio.aclose()
@@ -188,7 +187,7 @@ def _run_asyncio_task(
 
     cancel_scope = trio.CancelScope()
     aio_task_complete = trio.Event()
-    aio_err: Optional[BaseException] = None
+    aio_err: BaseException | None = None
 
     chan = LinkedTaskChannel(
         aio_q,  # asyncio.Queue
@@ -270,7 +269,7 @@ def _run_asyncio_task(
         '''
         nonlocal chan
         aio_err = chan._aio_err
-        task_err: Optional[BaseException] = None
+        task_err: BaseException | None = None
 
         # only to avoid ``asyncio`` complaining about uncaptured
         # task exceptions
@@ -350,11 +349,11 @@ async def translate_aio_errors(
     '''
     trio_task = trio.lowlevel.current_task()
 
-    aio_err: Optional[BaseException] = None
+    aio_err: BaseException | None = None
 
     # TODO: make thisi a channel method?
     def maybe_raise_aio_err(
-        err: Optional[Exception] = None
+        err: Exception | None = None
     ) -> None:
         aio_err = chan._aio_err
         if (