Error trying to install Ruby Gosu library (OS X)

I'm trying to install the ruby Gosu library with the sudo gem install gosu command, but it returns the following error message: ERROR: Error installing gosu: ERROR: Failed to build gem native extension. /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/bin/ruby extconf.rb The Gosu gem requires some libraries to be installed system-wide. See the following site for a list: https://github.com/jlnr/gosu/wiki/Getting-Started-on-OS-X creating Makefile make "DESTDIR=" make: *** No rule to make target /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/include/ruby-2.0.0/universal-darwin14/ruby/config.h', needed by stb_vorbis.o. Stop. Gem files will remain installed in /Library/Ruby/Gems/2.0.0/gems/gosu-0.10.4 for inspection. Results logged to /Library/Ruby/Gems/2.0.0/gems/gosu-0.10.4/ext/gosu/gem_make.out Can anyone help me?