regrtest: add the name of the failing test on a child error (-j option)
diff --git a/Lib/test/regrtest.py b/Lib/test/regrtest.py
index 0dcd550..0b7e3d2 100755
--- a/Lib/test/regrtest.py
+++ b/Lib/test/regrtest.py
@@ -637,7 +637,7 @@
                     assert result[1] == 'KeyboardInterrupt'
                     raise KeyboardInterrupt   # What else?
                 if result[0] == CHILD_ERROR:
-                    raise Exception("Child error: {}".format(result[1]))
+                    raise Exception("Child error on {}: {}".format(test, result[1]))
                 accumulate_result(test, result)
                 test_index += 1
         except KeyboardInterrupt: