--- a/h5fslib/__init__.py	Wed Apr 03 11:09:48 2013 +0200
+++ b/h5fslib/__init__.py	Sun Mar 31 00:16:42 2013 +0100
@@ -41,6 +41,8 @@
                   fetch_mp=True)
     server.parse(errex=1)
     _opts, ags = server.cmdline
+    if not ags:
+        return
     h5file = h5py.File(ags.pop(), 'r')
     try:
         server.h5file = h5file