How can I install Ruby 1.9.3 in Mac OS X Lion?

Question

I am trying to install Ruby 1.9.3 but am having problems. I installed RVM, then typed:

rvm install 1.9.3

The output says:

Answer 1

RVM needs gcc-4.2 to be able to install ruby 1.9.3. Unfortunately Lion does not include anymore gcc-4-2, just the llvm version:

lrwxr-xr-x  1 root  wheel  12 15 feb 17:21 /usr/bin/gcc -> llvm-gcc-4.2

If you have Lion but upgraded from Snow Leopard it is likely that you still have gcc-4.2 If you have a brand new installation of Lion you should download gcc-4.2. I recommned downloading this package.

https://github.com/kennethreitz/osx-gcc-installer

Check that you have gcc-4.2 installed now:

-rwxr-xr-x  1 root  wheel  113024 16 may  2011 /usr/bin/gcc-4.2
lrwxr-xr-x  1 root  wheel      12 15 feb 17:21 /usr/bin/gcc -> llvm-gcc-4.2

Now you can install ruby 1.9.3 as usual:

rvm install 1.9.3
rvm use 1.9.3 --default