I recently setup a new Mac (running Lion) for development using jruby. As I have done many times in the past, I installed Xcode (4.4) and proceeded to install the command line tools. Next comes rvm, and we are humming along, until it complains that gcc-4.2 is not in my path. But it is. I can see it with
gcc --version. In any case, the notes for rvm suggest using homebrew to install gcc-4.2 like so:
brew update brew tap homebrew/dupes brew install autoconf automake apple-gcc42 rvm pkg install openssl
Since I use homebrew to install other packages anyway, this worked out fine.
That took care of my problem, and I proceeded to install jruby as usual:
rvm install jruby