README.txt in graph-2.7.1 vs README.txt in graph-2.8.0

@@ -12,10 +12,10 @@
 coloring leaf nodes blue, outdated nodes red, and outdated leaf nodes
 purple (red+blue).
 
 OSX quick tip: 
 
-    % sudo gem install graph
+    % sudo gem install graph --development
     % sudo brew install graphviz
     % gem unpack graph
     % cd graph*
     % rake gallery
     % open gallery/*.png