When I try to install the mysql2 gem, it fails with no apparent errors. Does anyone know what to do to work around this so mysql2 installs? $ sudo gem install mysql2 Building native extensions. This could take a while... ERROR: Error installing mysql2: ERROR: Failed to build gem native extension. /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby extconf.rb checking for rb_thread_