Configure: error: clang version 3.0 or later is required - but I already have it

I'm trying to follow this RVM installation guide , supposedly for Snow Leopard 10.6.8 (I should point out that $ rvm -v returns -bash: rvm: command not found), but when I run $ curl -L https://get.rvm.io | bash -s stable --auto-dotfiles --autolibs=enable --rails it ends in this Error running './configure --prefix=/Users/mac/.rvm/rubies/ruby-2.2.0 --with-opt-dir=/usr/local/opt/libyaml:/usr/local/opt/readline:/usr/local/opt/libksba:/usr/local/opt/openssl --disable-install-doc --enable-shared', showing last 15 lines of /Users/mac/.rvm/log/1427567557_ruby-2.2.0/configure.log [2015-03-28 15:33:08] ./configure current path: /Users/mac/.rvm/src/ruby-2.2.0 PATH=/usr/local/opt/pkg-config/bin:/usr/local/opt/libtool/bin:/usr/local/opt/automake/bin:/usr/local/opt/autoconf/bin:/usr/local/bin:/usr/local/bin:/opt/local/bin:/opt/local/sbin:/Library/Frameworks/Python.framework/Versions/2.7/bin:/usr/bin/python:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/opt/X11/bin:/usr/local/git/bin:/usr/X11/bin:/Users/mac/.rvm/bin command(5): ./configure --prefix=/Users/mac/.rvm/rubies/ruby-2.2.0 --with-opt-dir=/usr/local/opt/libyaml:/usr/local/opt/readline:/usr/local/opt/libksba:/usr/local/opt/openssl --disable-install-doc --enable-shared config.guess already exists config.sub already exists checking build system type... i386-apple-darwin10.8.0 checking host system type... i386-apple-darwin10.8.0 checking target system type... i386-apple-darwin10.8.0 i686-apple-darwin10-gcc-4.2.1: error trying to exec 'cc1': execvp: No such file or directory i686-apple-darwin10-gcc-4.2.1: error trying to exec 'cc1': execvp: No such file or directory configure: error: clang version 3.0 or later is required There has been an error while running configure. Halting the installation. Then I ran: $ which clang /usr/bin/clang $ clang -v Apple clang version 3.0 (tags/Apple/clang-211.10.1) (based on LLVM 3.0svn) Target: x86_64-apple-darwin10.8.0 Thread model: posix I keep getting the same error message when I try to install RVM, even after restarting. There's clearly something weird about the fact that the target is 10.8.0 and that is *not even addressed in the guide*, so I really need actual help with this. Updating my OS isn't an option so please don't bring that up.