i was having some problems running green shoes on my 64bit linux box,
and eventually those problems were solved. here is how. (note: this
is to solve the problems right now they will be solved in the next
release of ruby-gtk2)
anyway, the meat & potatoes of the error was this:
/home/serialhex/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:36:inrequire’: uninitialized constant Gdk::Drawable (NameError)`
go find your gtk2 gem, it’s probably in gems/gtk2-1.0.0/ or something
(in my example it tells you very simply). for me it’s at:
/home/serialhex/.rvm/gems/ruby-1.9.2-p290/gems/gtk2-1.0.0/
go into the ext/gtk2 dir in there and open the file rbgtkinits.c
in that file, make 2 changes:
take line 240:
void Init_gtk_inits(void)
{
Init_gtk_gdk_gc(); <----- line 240
…
}
and move it to the end:
void Init_gtk_inits(void)
{
…
Init_gtk_gdk_gc(); <------ last
}
then, in that dir (on mine it’s
/home/serialhex/.rvm/gems/ruby-1.9.2-p290/gems/gtk2-1.0.0/ext/gtk2 )
run make, drink some water (or coffee, or red bull)
when that is done, copy gtk2.so to the lib dir:
$ cp gtk2.so …/…/lib
then go, and have fun with your gtk or green shoes app 
hex