Only use `greenback` if actor-runtime is up..

tractor/devx/_debug.py

@@ -682,7 +682,7 @@ async def pause(
     https://en.wikipedia.org/wiki/Breakpoint
 
     '''
-    __tracebackhide__ = True
+    # __tracebackhide__ = True
     actor = tractor.current_actor()
     pdb, undo_sigint = mk_mpdb()
     task_name = trio.lowlevel.current_task().name
@@ -836,11 +836,15 @@ async def pause(
 # runtime aware version which takes care of all .
 def pause_from_sync() -> None:
     print("ENTER SYNC PAUSE")
+    actor: tractor.Actor = tractor.current_actor(
+        err_on_no_runtime=False,
+    )
+    if actor:
         try:
             import greenback
-        __tracebackhide__ = True
+            # __tracebackhide__ = True
+
 
-        actor: tractor.Actor = tractor.current_actor()
             # task_can_release_tty_lock = trio.Event()
 
             # spawn bg task which will lock out the TTY, we poll
@@ -853,8 +857,11 @@ def pause_from_sync() -> None:
                     # release_lock_signal=task_can_release_tty_lock,
                 ))
             )
+
         except ModuleNotFoundError:
             log.warning('NO GREENBACK FOUND')
+    else:
+        log.warning('Not inside actor-runtime')
 
     db, undo_sigint = mk_mpdb()
     Lock.local_task_in_debug = 'sync'