show cmd in runjsontests.py
diff --git a/test/runjsontests.py b/test/runjsontests.py
index ffe033f..5230965 100644
--- a/test/runjsontests.py
+++ b/test/runjsontests.py
@@ -14,6 +14,7 @@
     Return int, unicode (for both Python 2 and 3).
     Note: os.popen().close() would return None for 0.
     """
+    print(cmd, file=sys.stderr)
     pipe = os.popen(cmd)
     process_output = pipe.read()
     try: