--- a/tests/hghave.py	Tue Aug 25 00:02:44 2015 -0400
+++ b/tests/hghave.py	Mon Aug 24 22:23:45 2015 -0400
@@ -427,3 +427,7 @@
 @check("pure", "running with pure Python code")
 def has_pure():
     return os.environ.get("HGTEST_RUN_TESTS_PURE") == "--pure"
+
+@check("slow", "allow slow tests")
+def has_slow():
+    return os.environ.get('HGTEST_SLOW') == 'slow'