title: How to fix "cc: error: unrecognized command line option '-Wshorten-64-to-32'" issue on Mac
body: <p>You may have following issue while compiling python packages on Mac:</p>
  
  <p><code>cc -fno-strict-aliasing -fno-common -dynamic -arch x86_64 -arch i386 -g -Os -pipe -fno-common -fno-strict-aliasing -fwrapv -DENABLE_DTRACE -DMACOSX -DNDEBUG -Wall -Wstrict-prototypes -Wshorten-64-to-32 -DNDEBUG -g -fwrapv -Os -Wall -Wstrict-prototypes -DENABLE_DTRACE -arch x86_64 -arch i386 -pipe -I/System/Library/Frameworks/Python.framework/Versions/2.7/include/python2.7 -c src/misaka.c -o build/temp.macosx-10.9-intel-2.7/src/misaka.o</code></p>
  
  <p><code>cc: error: unrecognized command line option '-Wshorten-64-to-32'</code></p>
  
  <p><code>error: command 'cc' failed with exit status 1</code></p>