I am always having trouble with installing fresh rvm instance, so here are all steps needed in fresh rvm to install new ruby 1.9.2 export ARCHFLAGS=”-arch x86_64″ export CC=gcc-4.2 rvm pkg install readline rvm pkg install iconv rvm pkg install zlib rvm install 1.9.2 -C –with-readline-dir=$rvm_path/usr –with-iconv-dir=$rvm_path/usr –with-zlib-dir=$rvm_path/usr