@@ -26,8 +26,11 @@ The format is based on [Keep a Changelog](https://keepachangelog.com).
 
 ### Fixed
 
-*   The flag `foo` no longer retains the value `bar` after `FLAGS.foo = bar`
-    fails due to a validation error.
+*   (flags) The flag `foo` no longer retains the value `bar` after
+    `FLAGS.foo = bar` fails due to a validation error.
+*   (testing) Fixed an issue caused by
+    [this Python 3.12.1 change](https://github.com/python/cpython/pull/109725)
+    where the test reporter crashes when all tests are skipped.
 
 ## 2.0.0 (2023-09-19)
 
 
@@ -361,6 +361,9 @@ def stopTest(self, test):
         test_name = test.id() or str(test)
         sys.stderr.write('No pending test case: %s\n' % test_name)
         return
+      if getattr(self, 'start_time', None) is None:
+        # startTest may not be called for skipped tests since Python 3.12.1.
+        self.start_time = self.time_getter()
       test_id = id(test)
       run_time = self.time_getter() - self.start_time
       result.set_run_time(run_time)
@@ -386,7 +389,7 @@ def stopTestRun(self):
       # reporting here.
       for test_id in self.pending_test_case_results:
         result = self.pending_test_case_results[test_id]
-        if hasattr(self, 'start_time'):
+        if getattr(self, 'start_time', None) is not None:
           run_time = self.suite.overall_end_time - self.start_time
           result.set_run_time(run_time)
           result.set_start_time(self.start_time)