Hi, I was thinking that it may time to update the GemSpec to support another
variable called required_ruby_implementation. Thus, I filled an enhancement
request
https://rubyforge.org/tracker/?func=detail&aid=27269&group_id=126&atid=578
At this time, the GemSpec supports required_ruby_version but
Presumably Macruby gems will be installed with macgem? Certainly, we
would not want to fork RubyGems, but since the Gem::Platform spec
exists shouldn't macgem only install gems whose Gem::Platform::RUBY is
MacRuby?
For projects like JRuby and Rubinius it makes sense to always have
Gem::Platform::
