Hi Jordon, Thanks for the idea. I tried it (arch -arch i386 macirb), but get the same error. Tim Jordon suggested: "does not contain a version for the current architecture" sounds like a 32-bit vs. 64-bit problem to me. MacRuby 0.4 has both i386 and x86_64 archs for macruby and macirb, on a capable system it will pick the x86_64 arch first, which means any frameworks you load while running that arch need to have x86_64 in their Framework/library/bundle as well. What happens if you try running with something like `arch -arch i386 macruby` or `arch -arch i386 macirb` instead?