diff --git a/tests/test-doctest.py b/tests/test-doctest.py
--- a/tests/test-doctest.py
+++ b/tests/test-doctest.py
@@ -72,6 +72,9 @@
 
 cwd = os.path.dirname(os.environ["TESTDIR"])
 
+if not os.path.isdir(os.path.join(cwd, ".hg")):
+    sys.exit(0)
+
 files = subprocess.check_output(
     "hg files --print0 \"%s\"" % fileset, shell=True, cwd=cwd,
 ).split(b'\0')