Rails script/console crashes when I press up button because of bug in readline

Question

This issue is intermittent, but pressing the up-arrow to get a previously entered command I'll get an error such as:

/Users/me/.rvm/gems/ruby-1.9.3-p194/gems/activesupport-2.3.14/lib/active_support/whiny_nil.rb:52:in `method_missing': undefined method `force_encoding' for nil:NilClass (NoMethodError)
    from /Users/me/.rvm/gems/ruby-1.9.3-p194/gems/rb-readline-0.4.2/lib/rbreadline.rb:3801:in `_rl_col_width'
    from /Users/me/.rvm/gems/ruby-1.9.3-p194/gems/rb-readline-0.4.2/lib/rbreadline.rb:2944:in `update_line'
    from /Users/me/.rvm/gems/ruby-1.9.3-p194/gems/rb-readline-0.4.2/lib/rbreadline.rb:3486:in `block in rl_redisplay'
    from /Users/me/.rvm/gems/ruby-1.9.3-p194/gems/rb-readline-0.4.2/lib/rbreadline.rb:3481:in `each'
    from /Users/me/.rvm/gems/ruby-1.9.3-p194/gems/rb-readline-0.4.2/lib/rbreadline.rb:3481:in `rl_redisplay'
    from /Users/me/.rvm/gems/ruby-1.9.3-p194/gems/rb-readline-0.4.2/lib/rbreadline.rb:4618:in `_rl_internal_char_cleanup'
    from /Users/me/.rvm/gems/ruby-1.9.3-p194/gems/rb-readline-0.4.2/lib/rbreadline.rb:4679:in `readline_internal_charloop'
    from /Users/me/.rvm/gems/ruby-1.9.3-p194/gems/rb-readline-0.4.2/lib/rbreadline.rb:4743:in `readline_internal'
    from /Users/me/.rvm/gems/ruby-1.9.3-p194/gems/rb-readline-0.4.2/lib/rbreadline.rb:4765:in `readline'
    from /Users/me/.rvm/gems/ruby-1.9.3-p194/gems/rb-readline-0.4.2/lib/readline.rb:40:in `readline'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb/input-method.rb:115:in `gets'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb.rb:139:in `block (2 levels) in eval_input'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb.rb:273:in `signal_status'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb.rb:138:in `block in eval_input'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb/ruby-lex.rb:188:in `call'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb/ruby-lex.rb:188:in `buf_input'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb/ruby-lex.rb:103:in `getc'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb/slex.rb:205:in `match_io'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb/slex.rb:75:in `match'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb/ruby-lex.rb:286:in `token'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb/ruby-lex.rb:262:in `lex'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb/ruby-lex.rb:233:in `block (2 levels) in each_top_level_statement'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb/ruby-lex.rb:229:in `loop'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb/ruby-lex.rb:229:in `block in each_top_level_statement'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb/ruby-lex.rb:228:in `catch'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb/ruby-lex.rb:228:in `each_top_level_statement'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb.rb:155:in `eval_input'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb.rb:70:in `block in start'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb.rb:69:in `catch'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb.rb:69:in `start'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/bin/irb:16:in `<main>'

Looks like the issue is in readline? How to resolve the issue? According to bundle list I have this version of readline:

• rb-readline (0.4.2)

Update: New error after updating with rvm pkg install readline per answer:

>/Users/me/.rvm/gems/ruby-1.9.3-p194/gems/rb-readline-0.4.2/lib/rbreadline.rb:2730:in `[]': no implicit conversion from nil to integer (TypeError)
    from /Users/me/.rvm/gems/ruby-1.9.3-p194/gems/rb-readline-0.4.2/lib/rbreadline.rb:2730:in `update_line'
    from /Users/me/.rvm/gems/ruby-1.9.3-p194/gems/rb-readline-0.4.2/lib/rbreadline.rb:3486:in `block in rl_redisplay'
    from /Users/me/.rvm/gems/ruby-1.9.3-p194/gems/rb-readline-0.4.2/lib/rbreadline.rb:3481:in `each'
    from /Users/me/.rvm/gems/ruby-1.9.3-p194/gems/rb-readline-0.4.2/lib/rbreadline.rb:3481:in `rl_redisplay'
    from /Users/me/.rvm/gems/ruby-1.9.3-p194/gems/rb-readline-0.4.2/lib/rbreadline.rb:4618:in `_rl_internal_char_cleanup'
    from /Users/me/.rvm/gems/ruby-1.9.3-p194/gems/rb-readline-0.4.2/lib/rbreadline.rb:4679:in `readline_internal_charloop'
    from /Users/me/.rvm/gems/ruby-1.9.3-p194/gems/rb-readline-0.4.2/lib/rbreadline.rb:4743:in `readline_internal'
    from /Users/me/.rvm/gems/ruby-1.9.3-p194/gems/rb-readline-0.4.2/lib/rbreadline.rb:4765:in `readline'
    from /Users/me/.rvm/gems/ruby-1.9.3-p194/gems/rb-readline-0.4.2/lib/readline.rb:40:in `readline'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb/input-method.rb:115:in `gets'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb.rb:139:in `block (2 levels) in eval_input'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb.rb:273:in `signal_status'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb.rb:138:in `block in eval_input'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb/ruby-lex.rb:188:in `call'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb/ruby-lex.rb:188:in `buf_input'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb/ruby-lex.rb:103:in `getc'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb/slex.rb:205:in `match_io'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb/slex.rb:75:in `match'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb/ruby-lex.rb:286:in `token'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb/ruby-lex.rb:262:in `lex'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb/ruby-lex.rb:233:in `block (2 levels) in each_top_level_statement'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb/ruby-lex.rb:229:in `loop'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb/ruby-lex.rb:229:in `block in each_top_level_statement'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb/ruby-lex.rb:228:in `catch'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb/ruby-lex.rb:228:in `each_top_level_statement'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb.rb:155:in `eval_input'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb.rb:70:in `block in start'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb.rb:69:in `catch'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/irb.rb:69:in `start'
    from /Users/me/.rvm/rubies/ruby-1.9.3-p194/bin/irb:16:in `<main>'

And I still get the old error, as well.

Answer 1

It's clearly a problem with rb-readline.

I usually install readline as an rvm package:

rvm pkg install readline

And don't use any readline specific stuff in my Gemfile.

You may also have a look at:

Problems with the rails console, RVM and readline