Expose whether unittest failed to tearDown().

expect_tests/unittest_helper.py

Index: expect_tests/unittest_helper.py
diff --git a/expect_tests/unittest_helper.py b/expect_tests/unittest_helper.py
index 8c6eb4782ded0e20836fc3a3d0a7d75f843c75f2..e8b5270c50bb2ae736632d8112669f22ec01fcaa 100644
--- a/expect_tests/unittest_helper.py
+++ b/expect_tests/unittest_helper.py
@@ -26,8 +26,14 @@ def _RunTestCaseSingle(test_case, test_name, test_instance=None):
   # class...
   test_instance = test_instance or test_case('__init__')
   test_instance.setUp()
+  test_instance._test_failed_with_exception = False
   try:
     return Result(getattr(test_instance, test_name)())
+  except KeyboardInterrupt:
+    raise
+  except:
+    test_instance._test_failed_with_exception = True
+    raise
   finally:
     test_instance.tearDown()