Shoes seems to be using the system ruby at some point...
This is using https://github.com/wasnotrice/shoes/tree/fix-main (at 274c739c03)
Note that the build runs on the machine that builds it, but not on a different machine. This makes me think that it works only because it can find the files it needs on the building machine but in the rvm-installed ruby. On the 64-bit machine, the architecture is different, so this won't work.
Running the 32-bit build on the 32-bit building machine
imac-2:MacOS eric$ ./shoes-launch
LOADED FEATURES
enumerator.so
/Users/eric/.rvm/rubies/ruby-1.9.3-p125/lib/ruby/1.9.1/i386-darwin10.8.0/enc/encdb.bundle
/Users/eric/.rvm/rubies/ruby-1.9.3-p125/lib/ruby/1.9.1/i386-darwin10.8.0/enc/trans/transdb.bundle
/Users/eric/.rvm/rubies/ruby-1.9.3-p125/lib/ruby/site_ruby/1.9.1/rubygems/defaults.rb
/Users/eric/.rvm/rubies/ruby-1.9.3-p125/lib/ruby/1.9.1/i386-darwin10.8.0/rbconfig.rb
/Users/eric/.rvm/rubies/ruby-1.9.3-p125/lib/ruby/site_ruby/1.9.1/rubygems/deprecate.rb
/Users/eric/.rvm/rubies/ruby-1.9.3-p125/lib/ruby/site_ruby/1.9.1/rubygems/exceptions.rb
/Users/eric/.rvm/rubies/ruby-1.9.3-p125/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb
/Users/eric/.rvm/rubies/ruby-1.9.3-p125/lib/ruby/site_ruby/1.9.1/rubygems.rb
DIR: /Users/eric/projects/shoes/Shoes.app/Contents/MacOS
LOAD PATH
/Users/eric/projects/shoes/Shoes.app/Contents/MacOS/ruby/lib/i386-darwin10.8.0
/Users/eric/projects/shoes/Shoes.app/Contents/MacOS/ruby/lib
/Users/eric/projects/shoes/Shoes.app/Contents/MacOS/lib
.
requiring shoes
finished requiring shoes
(process:70770): Pango-WARNING **: couldn't load font "Lacuna Not-Rotated 17.333984375px", falling back to "Sans Not-Rotated 17.333984375px", expect ugly output.
(process:70770): Pango-WARNING **: couldn't load font "Lacuna Not-Rotated 64.0009765625px", falling back to "Sans Not-Rotated 64.0009765625px", expect ugly output.
Running the 32-bit build on a 64-bit machine
huckle:MacOS eric$ ./shoes-launch
/Users/eric/.rvm/rubies/ruby-1.9.3-p125/lib/ruby/site_ruby/1.9.1/rubygems.rb:31:in `require': cannot load such file -- rbconfig (LoadError)
from /Users/eric/.rvm/rubies/ruby-1.9.3-p125/lib/ruby/site_ruby/1.9.1/rubygems.rb:31:in `<top (required)>'
from <internal:gem_prelude>:1:in `require'
from <internal:gem_prelude>:1:in `<compiled>'
LOADED FEATURES
enumerator.so
/Users/eric/.rvm/rubies/ruby-1.9.3-p125/lib/ruby/site_ruby/1.9.1/rubygems/defaults.rb
DIR: /Users/eric/tmp/shoes-32/Shoes.app/Contents/MacOS
LOAD PATH
/Users/eric/tmp/shoes-32/Shoes.app/Contents/MacOS/ruby/lib/i386-darwin10.8.0
/Users/eric/tmp/shoes-32/Shoes.app/Contents/MacOS/ruby/lib
/Users/eric/tmp/shoes-32/Shoes.app/Contents/MacOS/lib
.
requiring shoes
Error starting Shoes: uninitialized constant Encoding::UTF_7
/Users/eric/tmp/shoes-32/Shoes.app/Contents/MacOS/ruby/lib/uri/common.rb:868:in `<module:URI>'
/Users/eric/tmp/shoes-32/Shoes.app/Contents/MacOS/ruby/lib/uri/common.rb:12:in `<top (required)>'
/Users/eric/tmp/shoes-32/Shoes.app/Contents/MacOS/ruby/lib/uri.rb:104:in `require'
/Users/eric/tmp/shoes-32/Shoes.app/Contents/MacOS/ruby/lib/uri.rb:104:in `<top (required)>'
/Users/eric/tmp/shoes-32/Shoes.app/Contents/MacOS/ruby/lib/open-uri.rb:1:in `require'
/Users/eric/tmp/shoes-32/Shoes.app/Contents/MacOS/ruby/lib/open-uri.rb:1:in `<top (required)>'
/Users/eric/tmp/shoes-32/Shoes.app/Contents/MacOS/lib/shoes.rb:12:in `require'
/Users/eric/tmp/shoes-32/Shoes.app/Contents/MacOS/lib/shoes.rb:12:in `<top (required)>'
(eval):3:in `require'
(eval):3:in `<main>'
@tenderlove: https://twitter.com/tenderlove/status/185081481616564224