Cannot execute “rails console” due to an error with readline

问题

I cannot execute rails console due to this error:

localhost:TwitterForZombies wiz$ rails c
/Users/wiz/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/irb/completion.rb:9:in `require': dlopen(/Users/wiz/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/x86_64-darwin12.2.1/readline.bundle, 9): Library not loaded: /usr/local/opt/readline/lib/libreadline.6.2.dylib (LoadError)
  Referenced from: /Users/wiz/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/x86_64-darwin12.2.1/readline.bundle
  Reason: image not found - /Users/wiz/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/x86_64-darwin12.2.1/readline.bundle
    from /Users/wiz/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/irb/completion.rb:9:in `<top (required)>'
    from /Users/wiz/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/railties-3.2.9/lib/rails/commands/console.rb:3:in `require'
    from /Users/wiz/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/railties-3.2.9/lib/rails/commands/console.rb:3:in `<top (required)>'
    from /Users/wiz/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/railties-3.2.9/lib/rails/commands.rb:38:in `require'
    from /Users/wiz/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/railties-3.2.9/lib/rails/commands.rb:38:in `<top (required)>'
    from script/rails:6:in `require'
    from script/rails:6:in `<main>'

I have installed readline via homebrew. I'd like to keep using rbenv instead of rvm.

Thank you for reading my question.

回答1:

I had the same issue recently with homebrew and libreadline.7.x.dylib / libreadline.6.x.dylib

I solved it by running:

ln -s /usr/local/opt/readline/lib/libreadline.7.0.dylib /usr/local/opt/readline/lib/libreadline.6.dylib

source: https://github.com/rails/rails/issues/26658

回答2:

Homebrew is great, but once in a while it doesn't play nice with some of the other moving parts.

A brew update && brew upgrade brought in libreadline.7.x.dylib while automatically removing libreadline.6.x.dylib, which ruby was still relying on.

There may be more clever ways to fix the problem, but brute force worked for me:

$ rbenv uninstall 2.3.1
$ rbenv install 2.3.1
$ cd /path/to/my/app
$ bundle

The above assumes the presence of rbenv's ruby-build and, of course, bundler; replace 2.3.1 with whatever version of ruby you are using.

Please note that similar problems can occur with different homebrew-managed libraries (see my own answer to this, for example)

回答3:

I'm on OSX, ruby2.3.0, rails5. Adding gem 'rb-readline' to my Gemfile fixed this problem.

回答4:

I got the same error with Ruby 2.1.0, and rails 4.0. After searching and trying a lot, finally it work well:) Here are what I did:

rvm cleanup all
rvm autolibs enable
rvm install 2.1.0 

The other ways:

brew update
brew uninstall readline
brew install readline

The autolibs command will force RVM install all dependencies, so you don't need to worry about it.

Hope it's helpful.

回答5:

As Sachin hinted, installing readline and then reinstalling ruby is the ideal approach - but the details are a bit different for rbenv. Given your file paths, I'm guessing you're on a Mac, so the following should help:

brew install readline ruby-build
env CONFIGURE_OPTS=--with-readline-dir=`brew --prefix readline` rbenv install 1.9.3-p286

This was taken from the ruby-build Wiki and a quick google search.

回答6:

Using mac, El Captain version, it is possible to fix just by doing

rvm reinstall your_ruby_version

(like rvm reinstall ruby-2.3.1)

Hope this helps, good luck!

回答7:

taken from github user @enderahmetyurt (this is the only solution that worked for me).

Solution: Add gem 'rb-readline' to your Gemfile in development group and bundle install.

It's the easiest solution for silly "readline" errors.

回答8:

try installing readline, and reinstall your ruby

https://rvm.io/packages/readline/

来源：https://stackoverflow.com/questions/16756287/cannot-execute-rails-console-due-to-an-error-with-readline