次のエラーが表示されます。
/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/yaml.rb:4:in `<top (required)>':
It seems your ruby installation is missing psych (for YAML output).
To eliminate this warning, please install libyaml and reinstall your ruby.
/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:in `require': cannot load such file -- psych (LoadError)
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:in `require'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/yaml.rb:5:in `<top (required)>'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:in `require'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:in `require'
from /usr/local/bin/hub:190:in `<main>'
libyaml と psych に関連する Stack Overflow の提案を試しました。ただし、それらの多くは、次のエラーを返す rvm コマンドを必要とします。
rvm reinstall 2.0
/Users/richardburton/.rvm/src/ruby-2.0.0-p247 has already been removed.
Removing /Users/richardburton/.rvm/rubies/ruby-2.0.0-p247 - please wait
Error running '__rvm_rm_rf /Users/richardburton/.rvm/rubies/ruby-2.0.0-p247',
please read /Users/richardburton/.rvm/log/1401921952_ruby-2.0.0-p247/remove.rubies.log
Searching for binary rubies, this might take some time.
No binary rubies available for: osx/10.10/x86_64/ruby-2.0.0-p247.
明らかに、この段階で使用可能な rvm バイナリがあります。Ruby 2.0 を起動して実行する方法に関するヒントや提案をいただければ幸いです。
ありがとう!