I was trying run gem install json and got the following error Gem::Ext::BuildError: ERROR: Failed to build gem native extension. /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/bin/ruby extconf.rb creating Makefile make "DESTDIR=" clean make "DESTDIR=" compiling generator.c linking shared-object json/ext/generator.bundle clang: error: unknown argument: '-multiply_definedsuppress' [-Wunu