Disable long test timeouts when using a debugger (#2745)

Summary:
Pull Request resolved: #2745

Adds a logic to disable test timeouts when a debugger is detected.

Reviewed By: mgarrard

Differential Revision: D62244200

fbshipit-source-id: 806581972cae7df937ba1d1408d80d1ab2f392ca

ax/utils/common/testutils.py

@@ -306,8 +306,10 @@ def signal_handler(signum: int, frame: Optional[FrameType]) -> None:
                 message += (
                     " To see a profiler output, set `TestCase.PROFILE_TESTS` to `True`."
                 )
-
-            if self._long_test_active_reason is None:
+            if hasattr(sys, "gettrace") and sys.gettrace() is not None:
+                # If we're in a debugger session, let the test continue running.
+                return
+            elif self._long_test_active_reason is None:
                 message += (
                     " To specify a reason for a long running test,"
                     + " utilize the @ax_long_test decorator. If your test "