rubinius 2.0.0pre json gem

gistfile1.txt

conorhunt:~$ gem install json
Fetching: json-1.5.1.gem (100%)
Building native extensions.  This could take a while...
Successfully installed json-1.5.1
1 gem installed
conorhunt:~$ irb
rbx-2.0.0pre :001 > require 'json'
TypeError: wrong argument type NilClass (expected Module)
   from Rubinius::NativeMethod.load_extension at kernel/common/native_method.rb:43
   from Rubinius::CodeLoader#load_library at kernel/delta/codeloader.rb:180
   from Rubinius::CodeLoader#require at kernel/common/codeloader.rb:46
   from Rubinius::CodeLoader.require at kernel/common/codeloader.rb:145
   from Kernel(Module)#gem_original_require (require) at kernel/common/kernel.rb:781
   from Kernel(Module)#require at /Users/conorhunt/.rvm/rubies/rbx-2.0.0pre/lib/rubygems/custom_require.rb:29
   from JSON::Ext.__module_init__ (Ext) at /Users/conorhunt/.rvm/gems/rbx-2.0.0pre@json/gems/json-1.5.1/lib/json/ext.rb:15
   from JSON.__module_init__ (JSON) at /Users/conorhunt/.rvm/gems/rbx-2.0.0pre@json/gems/json-1.5.1/lib/json/ext.rb:6
   from Object#__script__ at /Users/conorhunt/.rvm/gems/rbx-2.0.0pre@json/gems/json-1.5.1/lib/json/ext.rb:3
   from Rubinius::CodeLoader.require at kernel/common/codeloader.rb:149
   from Kernel(Module)#gem_original_require (require) at kernel/common/kernel.rb:781
   from Kernel(Module)#require at /Users/conorhunt/.rvm/rubies/rbx-2.0.0pre/lib/rubygems/custom_require.rb:29
   from JSON.__module_init__ (JSON) at /Users/conorhunt/.rvm/gems/rbx-2.0.0pre@json/gems/json-1.5.1/lib/json.rb:6
   from Object#__script__ at /Users/conorhunt/.rvm/gems/rbx-2.0.0pre@json/gems/json-1.5.1/lib/json.rb:2
   from Rubinius::CodeLoader.require at kernel/common/codeloader.rb:149
   from Kernel(Object)#gem_original_require (require) at kernel/common/kernel.rb:781
   from Kernel(Object)#require at /Users/conorhunt/.rvm/rubies/rbx-2.0.0pre/lib/rubygems/custom_require.rb:32
   from { } in Object#irb_binding at (irb):1
   from Rubinius::BlockEnvironment#call_on_instance at kernel/common/block_environment.rb:72
rbx-2.0.0pre :002 > exit

I'm seeing this too.

I opened an issue for them on github - rubinius/rubinius#973 and I believe it was also reported here - rubinius/rubinius#976