First of all, I should mention that I run OSX 10.8 Mountain Lion.That said, let's see.
Get the latest version of RVM and check if I am missing any required package:
$ rvm get stable
$ rvm requirements
$ rvm pkg install openssl
Then, when I tried to install a gem, i got an error like the following:
ERROR: Loading command: install (LoadError)
cannot load such file -- openssl
That might be because there is an incorrect reference to the openssl config file, so, let's see where it did install, and then provide the correct path
$ find . -type f -name "openssl.cnf"
$ rvm install 2.0.0 --with-openssl-dir=[path_found_above] --verify-downloads 1
After that, everything went fine.
In order to check all ruby installations your system has, you can run:
$ rvm list
Version 2.0.0-p0 should be there, and if you want to make your default, do:
Even though you make any given ruby version the system's default, I humbly suggest creating gemsets per directory, with its own version of ruby and gems. For further reading about gemsets, check this out.
$ rvm --default use 2.0.0