I have pushed repository  with script I am going to use to migrate
Ruby packages in Fedora. It is pretty rough at now, but will see what
can we do with it. The most important is the f19.rb script , which is
responsible for the conversion of your .spec file to F19 compliant one.
In short, it does following changes:
1) ruby(abi) -> ruby(release)
2) gem install -> %gem_install
You my wonder what is the 2nd point. I am going to introduce
%gem_install macro , which will be responsible for gems installation
(as the name imply ;). The main reason is that RubyGems 2.0 changes how
the documentation is generated. I.e. by default, only RI documentation
is generated while we used to have RI as well as RDoc. This macro allows
us to specify various installation defaults globally, without need of
editing each .spec file every time.
You might admit, that it would be nice to macroize other parts .spec
file as well (such as 'gem build' or 'gem spec'), but I am running out
of time, so it will need to wait for next Fedora release.
As always, any feedback is welcome.