--- contrib/python/PyHamcrest/py2/hamcrest/core/core/allof.py   (index)
+++ contrib/python/PyHamcrest/py2/hamcrest/core/core/allof.py   (working tree)
@@ -25,7 +25,7 @@ class AllOf(BaseMatcher):
                 found_mismatch = True
                 if not self.describe_all_mismatches:
                     break
-                elif i < len(self.matchers) - 1:
+                elif i < len(self.matchers) - 1 and mismatch_description:
                     mismatch_description.append_text(' and ')
         return not found_mismatch