Rails控制台:在`require':无法加载这样的文件 - readline(LoadError)

Question

我的Rails应用程序中有一些错误,我试图通过发出以下命令来启动Rails控制台:

rails console

无论我尝试什么,我总是得到同样的错误:

/usr/local/rvm/rubies/ruby-2.1.1/lib/ruby/2.1.0/irb/completion.rb:9:in `require': cannot load such file -- readline (LoadError)
    from /usr/local/rvm/rubies/ruby-2.1.1/lib/ruby/2.1.0/irb/completion.rb:9:in `<top (required)>'
    from /opt/mammie/web/icosole/vendor/bundle/ruby/2.1.0/gems/railties-3.1.3/lib/rails/commands/console.rb:3:in `require'
    from /opt/mammie/web/icosole/vendor/bundle/ruby/2.1.0/gems/railties-3.1.3/lib/rails/commands/console.rb:3:in `<top (required)>'
    from /opt/mammie/web/icosole/vendor/bundle/ruby/2.1.0/gems/railties-3.1.3/lib/rails/commands.rb:37:in `require'
    from /opt/mammie/web/icosole/vendor/bundle/ruby/2.1.0/gems/railties-3.1.3/lib/rails/commands.rb:37:in `<top (required)>'
    from script/rails:6:in `require'
    from script/rails:6:in `<main>'

我真的尝试过在网上找到的所有可能的解决方案,因为很多人遇到了同样的错误.不幸的是,似乎没有任何效果.当我尝试以下命令时:

ruby /usr/local/rvm/src/ruby-2.1.1/ext/readline/extconf.rb

我得到以下输出

checking for tgetnum() in -lncurses... yes
checking for readline/readline.h... yes
checking for readline/history.h... yes
checking for readline() in -lreadline... no
checking for readline() in -ledit... no
checking for editline/readline.h... no
*** /usr/local/rvm/src/ruby-2.1.1/ext/readline/extconf.rb failed ***

表明缺少某些东西,但使用apt-get安装readline也没有任何区别.我猜它可能与不兼容的gem版本有关,因为控制台前一段时间曾短暂工作过.readline是否存在任何已知版本问题？很多人似乎都遇到过这个宝石的问题.

Answer 1

尝试rb-readline输入您的Gemfile并检查出来/sf/answers/671708901/

Answer 2

我终于找到了解决方案。这是几个问题的结合（gem 版本，冲突的 readline 库）。

首先，我重新获取了 readline 库

sudo apt-get install libreadline-dev

然后我卸载了ruby

rvm remove 2.1.1

我再次安装了 ruby

rvm install 2.1.1

我告诉 RVM 使用默认的 (2.1.1) Ruby

rvm use default

我重新安装了 Rails 和 readline

gem install rails
gem install readline

我再次启动控制台时出现错误，但略有不同：

/usr/local/rvm/rubies/ruby-2.1.1/lib/ruby/2.1.0/irb/completion.rb:9:in `require':  /usr/local/lib/libreadline.so.6: undefined symbol: UP - /usr/local/rvm/rubies/ruby-2.1.1/lib/ruby/2.1.0/x86_64-linux/readline.so (LoadError)
    from /usr/local/rvm/rubies/ruby-2.1.1/lib/ruby/2.1.0/irb/completion.rb:9:in `<top (required)>'
    from /opt/mammie/web/icosole/vendor/bundle/ruby/2.1.0/gems/railties-3.1.3/lib/rails/commands/console.rb:3:in `require'
    from /opt/mammie/web/icosole/vendor/bundle/ruby/2.1.0/gems/railties-3.1.3/lib/rails/commands/console.rb:3:in `<top (required)>'
    from /opt/mammie/web/icosole/vendor/bundle/ruby/2.1.0/gems/railties-3.1.3/lib/rails/commands.rb:37:in `require'
    from /opt/mammie/web/icosole/vendor/bundle/ruby/2.1.0/gems/railties-3.1.3/lib/rails/commands.rb:37:in `<top (required)>'
    from script/rails:6:in `require'
    from script/rails:6:in `<main>'

所以按照这个说明（http://vkarthickeyan.wordpress.com/2012/02/16/mysql-symbol-lookup-error-usrlocalliblibreadline-so-6-undefined-symbol-up/），我让它工作：

cd /usr/local/lib
mkdir temp
mv libreadline* temp
ldconfig
apt-get update

感谢 Hunterboerner 的帮助！

Answer 3

如果您正在运行Rails 4.x，则可能是Spring导致了此问题。

尝试停止春季过程 bundle exec spring stop

然后跑 bundle exec rails c