rails4_upgrade1.rb

$ rspec spec
/Users/foo/.rvm/gems/ruby-2.0.0-p353@bar/gems/activesupport-4.0.2/lib/active_support/dependencies.rb:229:in `require': cannot load such file -- active_support/base64 (LoadError)
        from /Users/foo/.rvm/gems/ruby-2.0.0-p353@bar/gems/activesupport-4.0.2/lib/active_support/dependencies.rb:229:in `block in require'
        from /Users/foo/.rvm/gems/ruby-2.0.0-p353@bar/gems/activesupport-4.0.2/lib/active_support/dependencies.rb:214:in `load_dependency'
        from /Users/foo/.rvm/gems/ruby-2.0.0-p353@bar/gems/activesupport-4.0.2/lib/active_support/dependencies.rb:229:in `require'
        from /Users/foo/.rvm/gems/ruby-2.0.0-p353@bar/bundler/gems/active_merchant-e555501cba35/lib/active_merchant.rb:33:in `<top (required)>'
        from /Users/foo/.rvm/gems/ruby-2.0.0-p353@bar/gems/activesupport-4.0.2/lib/active_support/dependencies.rb:229:in `require'
        from /Users/foo/.rvm/gems/ruby-2.0.0-p353@bar/gems/activesupport-4.0.2/lib/active_support/dependencies.rb:229:in `block in require'
        from /Users/foo/.rvm/gems/ruby-2.0.0-p353@bar/gems/activesupport-4.0.2/lib/active_support/dependencies.rb:214:in `load_dependency'
        from /Users/foo/.rvm/gems/ruby-2.0.0-p353@bar/gems/activesupport-4.0.2/lib/active_support/dependencies.rb:229:in `require'
        from /Users/foo/.rvm/gems/ruby-2.0.0-p353@bar/bundler/gems/active_merchant-e555501cba35/lib/activemerchant.rb:1:in `<top (required)>'
        from /Users/foo/.rvm/gems/ruby-2.0.0-p353@global/gems/bundler-1.3.5/lib/bundler/runtime.rb:72:in `require'
        from /Users/foo/.rvm/gems/ruby-2.0.0-p353@global/gems/bundler-1.3.5/lib/bundler/runtime.rb:72:in `block (2 levels) in require'
        from /Users/foo/.rvm/gems/ruby-2.0.0-p353@global/gems/bundler-1.3.5/lib/bundler/runtime.rb:70:in `each'
        from /Users/foo/.rvm/gems/ruby-2.0.0-p353@global/gems/bundler-1.3.5/lib/bundler/runtime.rb:70:in `block in require'
        from /Users/foo/.rvm/gems/ruby-2.0.0-p353@global/gems/bundler-1.3.5/lib/bundler/runtime.rb:59:in `each'
        from /Users/foo/.rvm/gems/ruby-2.0.0-p353@global/gems/bundler-1.3.5/lib/bundler/runtime.rb:59:in `require'
        from /Users/foo/.rvm/gems/ruby-2.0.0-p353@global/gems/bundler-1.3.5/lib/bundler.rb:132:in `require'
        from /Users/foo/test/bar/config/application.rb:7:in `<top (required)>'
        from /Users/foo/test/bar/config/environment.rb:2:in `require'
        from /Users/foo/test/bar/config/environment.rb:2:in `<top (required)>'
        from /Users/foo/test/bar/spec/spec_helper.rb:3:in `require'
        from /Users/foo/test/bar/spec/spec_helper.rb:3:in `<top (required)>'
        from /Users/foo/test/bar/spec/controllers/accounts_controller_spec.rb:1:in `require'
        from /Users/foo/test/bar/spec/controllers/accounts_controller_spec.rb:1:in `<top (required)>'
        from /Users/foo/.rvm/gems/ruby-2.0.0-p353@bar/gems/rspec-core-3.0.0.beta1/lib/rspec/core/configuration.rb:886:in `load'
        from /Users/foo/.rvm/gems/ruby-2.0.0-p353@bar/gems/rspec-core-3.0.0.beta1/lib/rspec/core/configuration.rb:886:in `block in load_spec_files'
        from /Users/foo/.rvm/gems/ruby-2.0.0-p353@bar/gems/rspec-core-3.0.0.beta1/lib/rspec/core/configuration.rb:886:in `each'
        from /Users/foo/.rvm/gems/ruby-2.0.0-p353@bar/gems/rspec-core-3.0.0.beta1/lib/rspec/core/configuration.rb:886:in `load_spec_files'
        from /Users/foo/.rvm/gems/ruby-2.0.0-p353@bar/gems/rspec-core-3.0.0.beta1/lib/rspec/core/command_line.rb:22:in `run'
        from /Users/foo/.rvm/gems/ruby-2.0.0-p353@bar/gems/rspec-core-3.0.0.beta1/lib/rspec/core/runner.rb:90:in `run'
        from /Users/foo/.rvm/gems/ruby-2.0.0-p353@bar/gems/rspec-core-3.0.0.beta1/lib/rspec/core/runner.rb:17:in `block in autorun'
        
        
        
Bug seems to be fixed here: 
https://github.com/Shopify/active_merchant/blob/master/lib/active_merchant.rb#L37


Bug is here in the repo we use:
https://github.com/vantran/active_merchant/blob/master/lib/active_merchant.rb#L33