Picky gives an error when trying to index japanese

application.rb

# encoding: utf-8
#
# TODO Adapt the generated example
#      (a library books finder) to what you need.
#
# Questions? Mail me, IRC #picky, the google group, http://github.com/floere/picky/wiki.
#
class PickySearch < Application

  # How text is indexed. Move to Index block to make it index specific.
  #
  indexing removes_characters: /[^a-zA-Z0-9\s\/\-\_\:\"\&\.]/i,
           stopwords:          /\b(and|the|of|it|in|for)\b/i,
           splits_text_on:     /[\s\/\-\_\:\"\&\/]/

  # How query text is preprocessed. Move to Search block to make it search specific.
  #
  searching removes_characters: /[^a-zA-Z0-9\s\/\-\_\&\.\"\~\*\:\,]/i, # Picky needs control chars *"~:, to pass through.
            stopwords:          /\b(and|the|of|it|in|for)\b/i,
            splits_text_on:     /[\s\/\-\&]+/,
            maximum_tokens: 5, # Amount of tokens used in a search (5 = default).
            substitutes_characters_with: CharacterSubstituters::WestEuropean.new # Normalizes special user input, Ä -> Ae, ñ -> n etc.

  japanese_index = Index::Memory.new :japanese do
    source Sources::CSV.new(:japanese, :german, :file => "data/development/japanese.tab", :col_sep => "\t")

    indexing :removes_characters => /[^\p{Han}\p{Katakana}\p{Hiragana}\s;]/,
             :stopwords =>         /\b(and|the|of|it|in|for)\b/i,
             :splits_text_on =>    /[\s;]/

    category :japanese, 
  end

end

gistfile1.txt

roger@roger-MS-7621:~/Dropbox/picky_experiments/japanese_test$ rackup
Loaded picky with environment 'development' in /home/roger/Dropbox/pick
y_experiments/japanese_test on Ruby 1.9.2.

WARNING: No routes defined for application configuration in Class.


Application PickySearch loaded.
14:13:05: "development:japanese:japanese": Loading index from cache.
/home/roger/.rvm/gems/ruby-1.9.2-p180/gems/yajl-ruby-0.8.2/lib/yajl.rb:
37:in `parse': invalid encoding symbol (EncodingError)
        from /home/roger/.rvm/gems/ruby-1.9.2-p180/gems/yajl-ruby-0.8.2
/lib/yajl.rb:37:in `parse'

japanese.tab

1	日本語; にほんご	Japanisch; Die japanische Sprache
2	食べる; たべる	Essen.