We were trying to avoid depending on RVM Rubies, because they get moved and deleted a lot, and that shouldn't stop our dev tools from working.
If you're on OS X, and installed via Homebrew, then the installer should have detected that system Ruby was too old and installed Ruby 2.0 from Homebrew for you.
If you're not on OS X, you'll need to either install Ruby 2.0 or later before installing gitsh, or if you want to work around our RVM avoidance, you can force the installer to use your current RVM Ruby: `RUBY=$(which ruby) ./configure`
If you're on OS X, and installed via Homebrew, then the installer should have detected that system Ruby was too old and installed Ruby 2.0 from Homebrew for you.
If you're not on OS X, you'll need to either install Ruby 2.0 or later before installing gitsh, or if you want to work around our RVM avoidance, you can force the installer to use your current RVM Ruby: `RUBY=$(which ruby) ./configure`