General typing fixes for `mypy`

tractor/_debug.py

@@ -739,13 +739,14 @@ def _set_trace(
     # last_f.f_globals['__tracebackhide__'] = True
 
     # start 2 levels up in user code
-    frame: FrameType = sys._getframe()
+    frame: Optional[FrameType] = sys._getframe()
     if frame:
         frame = frame.f_back  # type: ignore
 
-    if pdb and actor is not None:
+    if frame and pdb and actor is not None:
         log.pdb(f"\nAttaching pdb to actor: {actor.uid}\n")
-        # no f!#$&* idea!
+        # no f!#$&* idea, but when we're in async land
+        # we need 2x frames up?
         frame = frame.f_back
 
     else:

tractor/_spawn.py

@@ -307,7 +307,8 @@ async def new_proc(
         proc: Optional[trio.Process] = None
         try:
             try:
-                proc = await trio.lowlevel.open_process(spawn_cmd)
+                # TODO: needs ``trio_typing`` patch?
+                proc = await trio.lowlevel.open_process(spawn_cmd)  # type: ignore
 
                 log.runtime(f"Started {proc}")
 
@@ -334,6 +335,9 @@ async def new_proc(
                                     await proc.wait()
                 raise
 
+            # a sub-proc ref **must** exist now
+            assert proc
+
             portal = Portal(chan)
             actor_nursery._children[subactor.uid] = (
                 subactor, proc, portal)