ok, i think this is the proper way to fix bundler, see:

two patches:

a) bundler/settings.rb: should respect ruby_scope with @global_config
b) bundler/runtime.rb: should never mess up RUBYOPT and BUNDLE_GEMFILE,
                       otherwise it's really causing a lot of issues
                       whenever we're spawning another ruby process
                       which might have its own Gemfile other than
                       original Gemfile. see how rails running each
                       tests with spawning processes!