bundle update でエラー

Twitterのせいでこのblogがおろそかになっている。

>gem update

にてたくさん更新された後

>bundle update

するとuninitialized constant Syck::Syck (NameError)となってはまり中。
bundler-1.0.14をbundler-1.0.13に戻してみたが同様エラー
Syckって何?

C:\home\amaster>bundle update
Fetching source index for http://rubygems.org/
c:/ruby/lib/ruby/1.9.1/rubygems/specification.rb:289:in `load': uninitialized constant Syck::Syck (NameError)
        from c:/ruby/lib/ruby/1.9.1/rubygems/specification.rb:289:in `_load'
        from c:/ruby/lib/ruby/1.9.1/rubygems/spec_fetcher.rb:119:in `load'
        from c:/ruby/lib/ruby/1.9.1/rubygems/spec_fetcher.rb:119:in `fetch_spec'

        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/remote_specification.rb:47:in `_remote_specification'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/remote_specification.rb:53:in `method_missing'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:101:in `block in __dependencies'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:98:in `each'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:98:in `__dependencies'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:68:in `activate_platform'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:325:in `resolve_requirement'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:295:in `block in resolve'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:294:in `reverse_each'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:294:in `resolve'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:344:in `block in resolve_requirement'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:343:in `catch'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:343:in `resolve_requirement'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:295:in `block in resolve'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:294:in `reverse_each'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:294:in `resolve'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:344:in `block in resolve_requirement'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:343:in `catch'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:343:in `resolve_requirement'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:295:in `block in resolve'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:294:in `reverse_each'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:294:in `resolve'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:344:in `block in resolve_requirement'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:343:in `catch'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:343:in `resolve_requirement'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:295:in `block in resolve'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:294:in `reverse_each'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:294:in `resolve'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:344:in `block in resolve_requirement'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:343:in `catch'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:343:in `resolve_requirement'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:295:in `block in resolve'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:294:in `reverse_each'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:294:in `resolve'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:344:in `block in resolve_requirement'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:343:in `catch'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:343:in `resolve_requirement'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:295:in `block in resolve'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:294:in `reverse_each'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:294:in `resolve'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:344:in `block in resolve_requirement'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:343:in `catch'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:343:in `resolve_requirement'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:295:in `block in resolve'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:294:in `reverse_each'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:294:in `resolve'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:344:in `block in resolve_requirement'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:343:in `catch'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:343:in `resolve_requirement'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:295:in `block in resolve'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:294:in `reverse_each'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:294:in `resolve'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:344:in `block in resolve_requirement'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:343:in `catch'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:343:in `resolve_requirement'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:295:in `block in resolve'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:294:in `reverse_each'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:294:in `resolve'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:344:in `block in resolve_requirement'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:343:in `catch'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:343:in `resolve_requirement'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:295:in `block in resolve'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:294:in `reverse_each'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:294:in `resolve'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:344:in `block in resolve_requirement'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:343:in `catch'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:343:in `resolve_requirement'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:295:in `block in resolve'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:294:in `reverse_each'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:294:in `resolve'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:160:in `start'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:128:in `block in resolve'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:127:in `catch'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/resolver.rb:127:in `resolve'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/definition.rb:151:in `resolve'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/definition.rb:90:in `specs'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/definition.rb:85:in `resolve_remotely!'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/installer.rb:43:in `run'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/installer.rb:8:in `install'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/cli.rb:270:in `update'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/vendor/thor/task.rb:22:in `run'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/vendor/thor/invocation.rb:118:in `invoke_task'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/vendor/thor.rb:246:in `dispatch'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/lib/bundler/vendor/thor/base.rb:389:in `start'
        from c:/ruby/lib/ruby/gems/1.9.1/gems/bundler-1.0.14/bin/bundle:13:in `'
        from c:/ruby/bin/bundle:19:in `load'
        from c:/ruby/bin/bundle:19:in `
'