Building Matplotlib with OSX backend

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Hi, I have installed sagemath 8.0 on OSX without any issue and now I am trying to upgrade matplotlib so I can have interactive plots. Simply doing

sage -pip install -U matplotlib

results in the following error

building 'matplotlib.backends._macosx' extension
gcc -fno-strict-aliasing -I/Applications/SageMath/local/var/tmp/sage/build/python2-2.7.13.p1/include -DNDEBUG -g -fwrapv -O3 -Wall -Wno-unused -I/usr/local/include -I/usr/include -I/usr/X11/include -I/opt/X11/include -I. -I/Applications/SageMath/local/include/python2.7 -c src/_macosx.m -o build/temp.macosx-10.9-x86_64-2.7/src/_macosx.o
gcc: error: src/_macosx.m: Objective-C compiler not installed on this system
error: command 'gcc' failed with exit status 1

Setting the environment variable CC=clang doesn't help. Is there a way to use clang to compile matplotlib?

Thanks