JRuby 1.7.0 progress

[Bohuslav Kabrda]

Hi folks,
I'm writing a quick summary of what I managed to achieve with JRuby/Fedora implementation so far. You can try out my repo at [1] and see the progress of work on jruby.spec at [2].
- I have managed to remove the RubyGems copy from JRuby and make them work with our system RubyGems - I had to apply few JRuby specific patches there - two are already accepted upstream, but not merged into the 1.8 tree, one is still pending [3]. The updated RubyGems are also in the mentioned repo and please be careful when installing them, preferably use mock.*
- As a part of the RubyGems modifications, I have also prepared a sample gem (rubygem-json, also in the repository), with a rubygem-json-java subpackage, that provides Java extensions for JRuby.
- Pure Gems from Fedora now work with JRuby out of the box, no modification needed.
- "jgem" command works exactly as "gem", only using JRuby - nice, isn't it? :)
- load paths set has been brought much closer to MRI, which allowed most of the stuff I have done

TODO:
- I'm still unsure what is the best way to set up the Provides/Requires, so that RubyGems would be installable without MRI, only with JRuby. I guess we can live with JRuby dragging in Ruby, that's a small problem for now :)
- Some modifications to Guidelines will be needed, explaining how to build Gems/non-Gems for JRuby.
- I will also add a jruby-devel package with macros.jruby to match MRI's behaviour closely.

* The reason for this is, that I have also tried to introduce new naming scheme for Gems extensions dirs, which is not compatible with the current one. So far, the %gem_extdir was "/usr/lib[64]/gems/exts". With Rubinius and JRuby comming, there is a slight problem - extensions for JRuby should of course go under /usr/share/gems/exts, but Rubinius extensions would have problems, as they should go under %gem_extdir, too. Therefore, I'd like to propose this scheme for extension placement:
%gem_extdir %{_libdir}/gems/ruby # MRI
%xgem_extdir %{_libdir}/gems/rubinius # Rubinius, not sure if that should be named "xgem_extdir", what do the others think?
%jgem_extdir %{_datadir}/gems/jruby #JRuby # JRuby
This logic to implement this is very simple and it all goes to defaults/operating_system.rb in the updated rubygems package in my repo (specfile is a bit adjusted, too).
There is also a question of versioning these dirs, mainly Rubinius exts, but I'm leaving that for future, comment if you have any good ideas :)

Thanks goes to Charles Nutter for taking the JRuby RubyGems close to upstream, which was very important from Fedora integration POV :)

Slavek.

-- 
Regards,
Bohuslav "Slavek" Kabrda.

[1] http://bkabrda.fedorapeople.org/jruby/jruby.repo
[2] https://github.com/bkabrda/jruby.spec
[3] https://github.com/rubygems/rubygems/pull/371