O ri de Ruby não está funcionando - 'Dados Marshall são muito curtos'

Question

Estou rodando Lubuntu 13.10, eu instalei o Ruby (1.9.3p194), Gems (1.8.23), ri (4.1.1), rdoc e algumas gemas (Rails, RSpec, haml ...) do apt -get repositório. Quando tento rodar ri, me passa a seguinte mensagem:

$ ri Array
/var/lib/gems/1.9.1/gems/rdoc-4.1.1/lib/rdoc/store.rb:548:in 'load': marshal data too short (ArgumentError)
        from /var/lib/gems/1.9.1/gems/rdoc-4.1.1/lib/rdoc/store.rb:548:in 'block in load_cache'
        from /var/lib/gems/1.9.1/gems/rdoc-4.1.1/lib/rdoc/store.rb:547:in 'open'
        from /var/lib/gems/1.9.1/gems/rdoc-4.1.1/lib/rdoc/store.rb:547:in 'load_cache'
        from /var/lib/gems/1.9.1/gems/rdoc-4.1.1/lib/rdoc/ri/driver.rb:391:in 'block in initialize'
        from /var/lib/gems/1.9.1/gems/rdoc-4.1.1/lib/rdoc/ri/paths.rb:59:in 'block in each'
        from /var/lib/gems/1.9.1/gems/rdoc-4.1.1/lib/rdoc/ri/paths.rb:58:in 'each'
        from /var/lib/gems/1.9.1/gems/rdoc-4.1.1/lib/rdoc/ri/paths.rb:58:in 'each'
        from /var/lib/gems/1.9.1/gems/rdoc-4.1.1/lib/rdoc/ri/driver.rb:385:in 'initialize'
        from /var/lib/gems/1.9.1/gems/rdoc-4.1.1/lib/rdoc/ri/driver.rb:362:in 'new'
        from /var/lib/gems/1.9.1/gems/rdoc-4.1.1/lib/rdoc/ri/driver.rb:362:in 'run'
        from /var/lib/gems/1.9.1/gems/rdoc-4.1.1/bin/ri:12:in '<top (required)>'
        from /usr/local/bin/ri:23:in 'load'
        from /usr/local/bin/ri:23:in '<main>'hri Array
/var/lib/gems/1.9.1/gems/rdoc-4.1.1/lib/rdoc/store.rb:548:in 'load': marshal data too short (ArgumentError)
        from /var/lib/gems/1.9.1/gems/rdoc-4.1.1/lib/rdoc/store.rb:548:in 'block in load_cache'
        from /var/lib/gems/1.9.1/gems/rdoc-4.1.1/lib/rdoc/store.rb:547:in 'open'
        from /var/lib/gems/1.9.1/gems/rdoc-4.1.1/lib/rdoc/store.rb:547:in 'load_cache'
        from /var/lib/gems/1.9.1/gems/rdoc-4.1.1/lib/rdoc/ri/driver.rb:391:in 'block in initialize'
        from /var/lib/gems/1.9.1/gems/rdoc-4.1.1/lib/rdoc/ri/paths.rb:59:in 'block in each'
        from /var/lib/gems/1.9.1/gems/rdoc-4.1.1/lib/rdoc/ri/paths.rb:58:in 'each'
        from /var/lib/gems/1.9.1/gems/rdoc-4.1.1/lib/rdoc/ri/paths.rb:58:in 'each'
        from /var/lib/gems/1.9.1/gems/rdoc-4.1.1/lib/rdoc/ri/driver.rb:385:in 'initialize'
        from /var/lib/gems/1.9.1/gems/rdoc-4.1.1/lib/rdoc/ri/driver.rb:362:in 'new'
        from /var/lib/gems/1.9.1/gems/rdoc-4.1.1/lib/rdoc/ri/driver.rb:362:in 'run'
        from /var/lib/gems/1.9.1/gems/rdoc-4.1.1/bin/ri:12:in '<top (required)>'
        from /usr/local/bin/ri:23:in 'load'
        from /usr/local/bin/ri:23:in '<main>'

Ainda não encontrei nada útil no Google.

P: Como posso consertar isso, ou como posso instalar corretamente o Ruby e a ri Gem no Lubuntu 13.10?