Use toolchain 2.3.0, dont install gcc on mac

install/from-scratch.sh

@@ -34,6 +34,14 @@ else
     TENSORFLOW=
 fi
 
+if [ "$(uname)" == "Linux" ]; then
+    MYGCCPACKAGE="gcc=4.8.5"
+    MYLIBGCCPKG="libgcc=4.8.5"
+else
+    MYGCCPACKAGE=
+    MYLIBGCCPKG=
+fi
+
 # For a complete list of dependencies, please read:
 # https://gitlab.idiap.ch/bob/bob/wikis/Dependencies
 
@@ -75,8 +83,8 @@ ${CONDA} create --copy --yes -n ${NAME} \
   cyvlfeat=0.4.5 \
   docopt \
   ffmpeg=2.8.10 \
-  gcc=4.8.5 \
-  libgcc=4.8.5 \
+  ${MYGCCPACKAGE} \
+  ${MYLIBGCCPKG} \
   giflib=5.1.4 \
   ipdb=0.10.2 \
   ipython \
@@ -97,7 +105,7 @@ ${CONDA} create --copy --yes -n ${NAME} \
   sox=14.4.2 \
   sphinx_rtd_theme \
   ${TENSORFLOW} \
-  toolchain=2.1.0 \
+  toolchain=2.3.0 \
   vlfeat=0.9.20
 
 echo "[>>] Bye!"