Ruby crashing on Lion

Apparently Ruby doesn’t work well (or barely at all) with Lion and X Code 4.1

In fact, it crashes with gusto when compiled with X Code 4.1… UNLESS you know the magic words!

I’m unclear how ruby 1.8.7 crashes and burns, but 1.9.2-p290 crashes with annoying (yet seemingly random) regularity. It looks like, at the minimum, threading is definitely having a problem with LLVM. You can test it out yourself, if you have had the misfortune of installing ruby on Lion before reading this…

# This will make  LLVM compiled OS-X Ruby
# fall down and go boom.
Fiber.new {}.resume

Fortunately, the fix is simple. Put this in your ~/.bashrc or equivalent-shell-startup file:

export CC=/usr/bin/gcc-4.2

That line forces any project to compile using GNU gcc instead of LLVM’s gcc. Not ideal, but at least Ruby works.

If you’ve already installed a ruby or two or compiled any native extensions using the llvm-gcc then you’ll have to remove them (replace the ruby version with version you’re working with):

$ rvm remove ruby-1.9.2-p290
$ rvm install ruby-1.9.2-p290
$ gem pristine --all          # Rebuilds all natively built gems
                              # ...repeat for all gemsets. *sigh*

I went for the nuclear option since I wasn’t sure what was broken and what okay. Warning: this command will destroy everything in ~/.rvm, including any customizations you’ve set therein.

rvm implode
bash < <(curl -s https://rvm.beginrescueend.com/install/rvm)

Then I had to reinstall all the rubies I use and reset up any gemsets.

I hope this helps someone.