Não foi possível instalar o Ruby com o RVM

Estou tendo problemas para instalar o Ruby com o RVM, e este me deixou perplexo. Estou executando o OS Mavericks, com as mais recentes ferramentas de linha de comando XCode e xcode. Eu tenho um (idêntico ao meu conhecimento) configurado em outra máquina sem problemas.

O RVM pareceu instalar sem problemas.

Após uma tentativa de instalação do rvm 2.1, recebi a seguinte mensagem de erro:

ruby-2.1.1 - #removing src/ruby-2.1.1..
Searching for binary rubies, this might take some time.
No binary rubies available for: osx/10.9/x86_64/ruby-2.1.1.
Continuing with compilation. Please read 'rvm help mount' to get more information on binary rubies.
Checking requirements for osx.
Certificates in '/usr/local/etc/openssl/cert.pem' already are up to date.
Requirements installation successful.
Installing Ruby from source to: /Users/user/.rvm/rubies/ruby-2.1.1, this may take a while depending on your cpu(s)...
ruby-2.1.1 - #downloading ruby-2.1.1, this may take a while depending on your connection...
ruby-2.1.1 - #extracting ruby-2.1.1 to /Users/user/.rvm/src/ruby-2.1.1...
ruby-2.1.1 - #applying patch /Users/user/.rvm/patches/ruby/changeset_r45225.diff.
ruby-2.1.1 - #applying patch /Users/user/.rvm/patches/ruby/changeset_r45240.diff.
ruby-2.1.1 - #configuring.

Error running './configure --prefix=/Users/user/.rvm/rubies/ruby-2.1.1 --with-opt-dir=/usr/local/opt/libyaml:/usr/local/opt/readline:/usr/local/opt/libksba:/usr/local/opt/openssl --enable-shared',
showing last 15 lines of /Users/user/.rvm/log/1394918736_ruby-2.1.1/configure.log
[2014-03-15 21:25:55] ./configure
current path: /Users/user/.rvm/src/ruby-2.1.1
PATH=/usr/local/opt/pkg-config/bin:/usr/local/opt/libtool/bin:/usr/local/opt/automake/bin:/usr/local/opt/autoconf/bin:/opt/local/bin:/opt/local/sbin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/Users/user/.rvm/bin
command(4): ./configure --prefix=/Users/user/.rvm/rubies/ruby-2.1.1 --with-opt-dir=/usr/local/opt/libyaml:/usr/local/opt/readline:/usr/local/opt/libksba:/usr/local/opt/openssl --enable-shared
checking build system type... x86_64-apple-darwin13.1.0
checking host system type... x86_64-apple-darwin13.1.0
checking target system type... x86_64-apple-darwin13.1.0
<stdin>:2:3: error: #error premature clang
        #error premature clang
         ^
1 error generated.
configure: error: clang version 3.0 or later is required
There has been an error while running configure. Halting the installation.

Meu primeiro pensamento foi executar requisitos de RVM, o que resultou em outra mensagem de erro

Checking requirements for osx.
Installing requirements for osx.
Updating system....
Installing required packages: gcc46.....
Error running 'requirements_osx_brew_libs_install gcc46',
showing last 15 lines of /Users/user/.rvm/log/1394919146/package_install_gcc46.log
+ case "$1" in
+ [[ -t 1 ]]
+ return 1
+ printf %b 'There were package installation errors, make sure to read the log.

Try `brew tap --repair` and make sure `brew doctor` looks reasonable.

Check Homebrew requirements https://github.com/mxcl/homebrew/wiki/Installation\n'
There were package installation errors, make sure to read the log.

Try `brew tap --repair` and make sure `brew doctor` looks reasonable.

Check Homebrew requirements https://github.com/mxcl/homebrew/wiki/Installation
+ case "$_system_version" in
+ return 1
Requirements installation failed with status: 1.

Segui o conselho aqui e passei horas pesquisando on-line, mas nenhuma solução ainda funcionou para mim. Quaisquer pensamentos e idéias são bem-vindos - esse aqui me deixou perplexo.