diff -r 06825f3aa213 -r 7cb2daf6da35 virtualenv/web/res/doc_requirements.txt
--- a/virtualenv/web/res/doc_requirements.txt	Fri Apr 13 12:43:08 2018 +0200
+++ b/virtualenv/web/res/doc_requirements.txt	Fri Apr 13 15:41:00 2018 +0200
@@ -1,2 +1,3 @@
 sphinx
 sphinx-autobuild
+#pygraphviz --install-option="--include-path=/usr/local/include" --install-option="--library-path=/usr/local/lib"