I am very happy with OS X Mavericks, by and large. It’s slightly more refined than Mountain Lion, and noticeably faster.

I also noted with pleasure that it installed Ruby 2.0 by default, instead of maintaining the out of date Ruby 1.8.

However, yesterday I tried running a script that invokes a module which i wrote that uses rubycocoa. It doesn’t work. A little digging reveals that rubycocoa is not (yet?) supported on either ruby 1.9 or 2.0. While there is a Mavericks update for rubycocoa, it just makes it work with versions 1.8. While I could live with that, since rvm does a good job of managing this sort of thing, in the case of rubycocoa, rvm has come up short. If I explicitly invoke the script with

#!/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby

It works, but

rvm use 1.8

#!/usr/bin/env ruby

fails with

/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:45:in `require’: cannot load such file — osx/cocoa (LoadError)
    from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:45:in `require’

Sigh.