由于readline中的错误，我按下按钮时Rails脚本/控制台崩溃

Question

此问题是间歇性的，但按向上箭头以获取先前输入的命令我将收到错误，例如：

/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>'

看起来问题是在readline中？ 如何解决这个问题？ 根据bundle list我有这个版本的readline：

• rb-readline（0.4.2）

更新 ：使用rvm pkg install readline每个答案更新后出现新错误：

>/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>'

而且我仍然会得到旧的错误。

Answer 1

这显然是rb-readline的一个问题。

我通常将readline安装为rvm包：

rvm pkg install readline

并且不要在我的Gemfile中使用任何readline特定的东西。

你也可以看看：

rails控制台，RVM和readline的问题

Answer 2

我今天遇到了这个。

我相信这是因为readline试图解析控制台行上的一些文本。 有些文字不能很好地发挥作用。

那么为什么关键呢？

这恰好是在我粘贴了一堆'stuff'来设置变量之后。 我显然在粘贴中出了问题，因为控制台崩溃了。

在崩溃之后，所有IT专业人员都会做些什么？ 再试一遍。 什么是尝试在rails控制台中编写的最后一个命令的最快方法？ 向上键。

一个很好的解决方法就是不要点击向上键或清除历史记录以删除违规行。