diff -up src/sage/graphs/graph_generators.py.orig src/sage/graphs/graph_generators.py
--- src/sage/graphs/graph_generators.py.orig	2015-10-11 17:55:39.963810018 -0300
+++ src/sage/graphs/graph_generators.py	2015-10-11 17:55:46.861810283 -0300
@@ -838,8 +838,7 @@ class GraphGenerators():
             >A geng -d0D3 n=4 e=0-6
         """
         import subprocess
-        from sage.misc.package import is_package_installed
-        if not is_package_installed("nauty"):
+        if 1:
             raise TypeError("the optional nauty package is not installed")
         sp = subprocess.Popen("geng {0}".format(options), shell=True,
                               stdin=subprocess.PIPE, stdout=subprocess.PIPE,