diff -up src/sage/graphs/graph_generators.py.orig src/sage/graphs/graph_generators.py
--- src/sage/graphs/graph_generators.py.orig 2019-06-26 14:41:04.000000000 -0600
+++ src/sage/graphs/graph_generators.py 2019-06-27 11:37:46.100759559 -0600
@@ -907,7 +907,7 @@ class GraphGenerators():
else:
enc_kwargs = {'encoding': 'latin-1'}
- sp = subprocess.Popen("geng {0}".format(options), shell=True,
+ sp = subprocess.Popen("nauty-geng {0}".format(options), shell=True,
stdin=subprocess.PIPE, stdout=subprocess.PIPE,
stderr=subprocess.PIPE, close_fds=True,
**enc_kwargs)