Single-step through trio without falling asleep

gistfile1.txt

--- Lib/pdb.py	2018-02-15 14:49:47.668435454 +0100
+++ ../pdb.py	2018-02-21 14:48:21.039713323 +0100
@@ -246,6 +246,10 @@
         that we ever need to stop in this function."""
         if self._wait_for_mainpyfile:
             return
+        if self.force_step(frame):
+           self.onecmd("step")
+           self.forget()
+           return
         if self.stop_here(frame):
             self.message('--Call--')
             self.interaction(frame, None)
@@ -257,7 +261,10 @@
                 or frame.f_lineno <= 0):
                 return
             self._wait_for_mainpyfile = False
-        if self.bp_commands(frame):
+        if self.force_step(frame):
+           self.onecmd("step")
+           self.forget()
+        elif self.bp_commands(frame):
             self.interaction(frame, None)
 
     def bp_commands(self, frame):
@@ -288,15 +295,39 @@
         """This function is called when a return trap is set here."""
         if self._wait_for_mainpyfile:
             return
+        if self.force_step(frame):
+           self.onecmd("step")
+           self.forget()
+           return
         frame.f_locals['__return__'] = return_value
         self.message('--Return--')
         self.interaction(frame, None)
 
+    def force_step(self, frame):
+        if "/trio/" in frame.f_code.co_filename:
+            return True
+        if "/pytest_trio/" in frame.f_code.co_filename:
+            return True
+        if "/async_generator/" in frame.f_code.co_filename:
+            return True
+        if "/sortedcontainers/" in frame.f_code.co_filename:
+            return True
+        if frame.f_code.co_filename.startswith("<attrs generated "):
+            return True
+        if frame.f_code.co_filename.endswith("/contextlib.py"):
+            return True
+        if frame.f_code.co_name == "getcoroutinestate":
+            return True
+
     def user_exception(self, frame, exc_info):
         """This function is called if an exception occurs,
         but only if we are to stop at or just below this level."""
         if self._wait_for_mainpyfile:
             return
+        if self.force_step(frame):
+           self.onecmd("step")
+           self.forget()
+           return
         exc_type, exc_value, exc_traceback = exc_info
         frame.f_locals['__exception__'] = exc_type, exc_value