Rubinius group file permission bug

rbx_group_perm_bug.sh

>> id
uid=1000(aumgn) gid=1000(aumgn) groups=1000(aumgn),10(wheel),18(dialout),1001(vboxsf)

>> ll debug.rb
-rw-rw----. 1 aumgn aumgn 10 Oct 31 14:31 debug.rb

>> ruby -v
rubinius 2.0.0dev (1.9.3 release yyyy-mm-dd JI) [i686-pc-linux-gnu]

>> cat debug.rb
puts 'Ok'

>> ruby debug.rb
Ok

>> sudo chown root:aumgn debug.rb

>> ruby debug.rb
Ok

>> sudo chown root:wheel debug.rb

>> ruby debug.rb
An exception occurred running debug.rb
    no such file to load -- debug.rb (LoadError)

Backtrace:
   Rubinius::CodeLoader#load_error at kernel/common/codeloader.rb:389
  Rubinius::CodeLoader#load_script at kernel/delta/codeloader.rb:63
  Rubinius::CodeLoader.load_script at kernel/delta/codeloader.rb:118
           Rubinius::Loader#script at kernel/loader.rb:614
             Rubinius::Loader#main at kernel/loader.rb:815