poller: add more debug to stopping

poller doesn't seem to dump state correctly when exiting. It splats:

Traceback (most recent call last):
  File "nipa/pw_poller.py", line 277, in <module>
    poller.run(life)
  File "nipa/pw_poller.py", line 256, in run
    worker.join()
  File "/usr/lib64/python3.12/threading.py", line 1147, in join
    self._wait_for_tstate_lock()
  File "/usr/lib64/python3.12/threading.py", line 1167, in _wait_for_tstate_lock
    if lock.acquire(block, timeout):
       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Add a log message and a handler, just in case.

Signed-off-by: Jakub Kicinski <[email protected]>

core/tester.py

@@ -96,6 +96,8 @@ def run(self) -> None:
             self.done_queue.put(s)
             core.log("Tester done processing")
 
+        core.log("Tester exiting")
+
     def load_tests(self, name):
         core.log_open_sec(name.capitalize() + " tests")
         tests_subdir = os.path.join(self.config.get('dirs', 'tests'), name)

pw_poller.py

@@ -246,6 +246,8 @@ def run(self, life) -> None:
                 if secs > 0:
                     log("Sleep", secs)
                 log_end_sec()
+        except KeyboardInterrupt:
+            pass  # finally will still run, but don't splat
         finally:
             log_open_sec(f"Stopping threads")
             for worker in self._workers: