There was already an if for linux

install/from-scratch.sh

@@ -30,14 +30,10 @@ fi
 
 if [ "$(uname)" == "Linux" ]; then
     TENSORFLOW=tensorflow
-else
-    TENSORFLOW=
-fi
-
-if [ "$(uname)" == "Linux" ]; then
     MYGCCPACKAGE="gcc=4.8.5"
     MYLIBGCCPKG="libgcc=4.8.5"
 else
+    TENSORFLOW=
     MYGCCPACKAGE=
     MYLIBGCCPKG=
 fi