Rails console: in `require': cannot load such file -- readline (LoadError)

Try putting rb-readline in your Gemfile and check this out https://stackoverflow.com/a/9595841/1905235

If you are running Rails 4.x it is possible that Spring is causing this issue.

Try stopping the Spring process bundle exec spring stop

Then run bundle exec rails c

I finally found a solution. It was a conjunction of several issues (gem versions, conflicting readline libraries).

Firstly, I refetched the readline lib

sudo apt-get install libreadline-dev

Then I uninstalled ruby

rvm remove 2.1.1

I installed ruby again

rvm install 2.1.1

I told RVM to use the default (2.1.1) Ruby

rvm use default

I reinstalled Rails and readline

gem install railsgem install readline

I got an error again launching the console, but a slightly different one:

/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>'

So following this instructions (http://vkarthickeyan.wordpress.com/2012/02/16/mysql-symbol-lookup-error-usrlocalliblibreadline-so-6-undefined-symbol-up/), I got it to work:

cd /usr/local/libmkdir tempmv libreadline* templdconfigapt-get update

Thanks to hunterboerner for the help!