Loading local variables into an IRB session: matz vs. rbx

gistfile1.txt

$ cat foo.rb 
s = 'foo'


ruby-1.9.2-p180 :008 > eval File.read('foo.rb')
 => "foo" 
ruby-1.9.2-p180 :009 > s
NameError: undefined local variable or method `s' for main:Object
        from (irb):9
        from /Users/rmichael/.rvm/rubies/ruby-1.9.2-p180/bin/irb:16:in `<main>'



rbx-1.2.3-20110315 :002 > eval File.read('foo.rb')
 => "foo" 
rbx-1.2.3-20110315 :003 > s
 => "foo" 

AFAICT, Matz answered here about this. This one of the reason why in a recent project (you know which one :)) I replaced the eval's by simple YAML.load's.