Update debug examples + harden `test_debugger`

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

examples/debugging/multi_daemon_subactors.py

@@ -27,12 +27,9 @@ async def main():
     '''
     async with tractor.open_nursery(
         debug_mode=True,
-        loglevel='cancel',
+    ) as an:
-        # loglevel='devx',
+        p0 = await an.start_actor('bp_forever', enable_modules=[__name__])
-    ) as n:
+        p1 = await an.start_actor('name_error', enable_modules=[__name__])
-
-        p0 = await n.start_actor('bp_forever', enable_modules=[__name__])
-        p1 = await n.start_actor('name_error', enable_modules=[__name__])
 
         # retreive results
         async with p0.open_stream_from(breakpoint_forever) as stream:

examples/debugging/multi_nested_subactors_error_up_through_nurseries.py

@@ -67,7 +67,7 @@ async def main():
     """
     async with tractor.open_nursery(
         debug_mode=True,
-        # loglevel='cancel',
+        loglevel='pdb',
     ) as n:
 
         # spawn both actors

examples/debugging/root_cancelled_but_child_is_in_tty_lock.py

@@ -39,8 +39,8 @@ async def main():
     '''
     async with tractor.open_nursery(
         debug_mode=True,
-        loglevel='devx',
+        enable_transports=['uds'],  # TODO, apss this via osenv?
-        enable_transports=['uds'],
+        loglevel='devx',  # XXX, required for test!
     ) as n:
 
         # spawn both actors

examples/debugging/root_timeout_while_child_crashed.py

@@ -1,4 +1,3 @@
-
 import trio
 import tractor
 
@@ -9,16 +8,22 @@ async def key_error():
 
 
 async def main():
-    """Root dies 
+    '''
+    Root is fail-after-cancelled while blocking and child RPC fails
+    simultaneously.
 
-    """
+    '''
     async with tractor.open_nursery(
         debug_mode=True,
-        loglevel='debug'
+        # loglevel='debug'  # ?XXX required?
     ) as n:
 
         # spawn both actors
         portal = await n.run_in_actor(key_error)
+        print(
+            f'Child is up @ {portal.chan.aid.reprol()}'
+        )
+
 
         # XXX: originally a bug caused by this is where root would enter
         # the debugger and clobber the tty used by the repl even though

examples/debugging/subactor_bp_in_ctx.py

@@ -36,6 +36,11 @@ async def just_bp(
 
 async def main():
 
+    # !TODO, parametrize the --tpt-proto={key} with osenv vars just
+    # like we do for loglevel/spawn-backend!
+    # - [ ] run on both tpts for all such debugger tests?
+    # - [ ] special skip for macos!
+    #
     if platform.system() != 'Darwin':
         tpt = 'uds'
     else:

examples/debugging/subactor_error.py

@@ -9,7 +9,6 @@ async def name_error():
 async def main():
     async with tractor.open_nursery(
         debug_mode=True,
-        # loglevel='transport',
     ) as an:
 
         # TODO: ideally the REPL arrives at this frame in the parent,

tests/devx/conftest.py

@@ -269,13 +269,10 @@ def ctlc(
 
 def expect(
     child,
-
+    patt: str,  # often a `pdbp`-prompt
-    # normally a `pdb` prompt by default
-    patt: str,
-
     **kwargs,
 
-) -> None:
+) -> str:
     '''
     Expect wrapper that prints last seen console
     data before failing.
@@ -286,6 +283,8 @@ def expect(
             patt,
             **kwargs,
         )
+        before = str(child.before.decode())
+        return before
     except TIMEOUT:
         before = str(child.before.decode())
         print(before)

tests/devx/test_debugger.py

@@ -765,6 +765,7 @@ def test_multi_subactors_root_errors(
 def test_multi_nested_subactors_error_through_nurseries(
     ci_env: bool,
     spawn: PexpectSpawner,
+    start_method: str,
 
     # TODO: address debugger issue for nested tree:
     # https://github.com/goodboy/tractor/issues/320
@@ -781,16 +782,16 @@ def test_multi_nested_subactors_error_through_nurseries(
     # A test (below) has now been added to explicitly verify this is
     # fixed.
 
-    child = spawn('multi_nested_subactors_error_up_through_nurseries')
+    child = spawn(
-
+        'multi_nested_subactors_error_up_through_nurseries',
-    # timed_out_early: bool = False
+        loglevel='pdb',
-
+    )
     for (
         i,
         send_char,
     ) in enumerate(itertools.cycle(['c', 'q'])):
 
-        timeout: float = -1
+        timeout: float = child.timeout
         if (
             _non_linux
             and
@@ -803,6 +804,15 @@ def test_multi_nested_subactors_error_through_nurseries(
         elif i == 0:
             timeout = 5
 
+        # XXX forking backends may take longer due to
+        # determinstic IPC cancellation.
+        if (
+            start_method in [
+                'main_thread_forkserver',
+            ]
+        ):
+            timeout += 4
+
         try:
             child.expect(
                 PROMPT,
@@ -1187,7 +1197,11 @@ def test_ctxep_pauses_n_maybe_ipc_breaks(
     mashed and zombie reaper kills sub with no hangs.
 
     '''
-    child = spawn('subactor_bp_in_ctx')
+    child = spawn(
+        'subactor_bp_in_ctx',
+        loglevel='devx'
+        # ^XXX REQUIRED for below patt matching!
+    )
     child.expect(PROMPT)
 
     # 3 iters for the `gen()` pause-points
@@ -1277,7 +1291,11 @@ def test_crash_handling_within_cancelled_root_actor(
     call.
 
     '''
-    child = spawn('root_self_cancelled_w_error')
+    child = spawn(
+        'root_self_cancelled_w_error',
+        loglevel='cancel',
+        # ^XXX REQUIRED for below patt matching!
+    )
     child.expect(PROMPT)
 
     assert_before(