No Such File to Load - Readline

rails console require cannot load such file readline

Readline gem is required by your application but not specified in your Gemfile

Please add this to your gem file

gem 'rb-readline'

Also reinstall

libreadline-dev

no such file to load -- readline

The readline module is normally part of the Ruby package itself.

Did you manually build your Ruby install? If so, you want to make sure libreadline and its headers are installed, and build again.

On Debian/Ubuntu:

apt-get install libreadline-dev

Or on RHEL/CentOS, try

yum install readline-devel

Update:

You are using a very old release of Ubuntu. If you want to keep using it, open /etc/apt/sources.list in a text editor, and change all occurrences of archive.ubuntu.com to old-releases.ubuntu.com. Then, run apt-get update and try the above again.

I urge you to consider updating your installation, though. Ubuntu 7.10 hasn't seen security updates in quite a while, and using it in production is not recommended. Even if it's not a production machine, there's a good chance you'll run into further problems because of old versions of certain libraries/dependencies.

no such file to load -- readline (Load Error)

I must check rvm requirements and ensure that all packages were installed.
Then reintall ruby:

rvm reinstall 1.9.2
Removing /usr/local/rvm/src/ruby-1.9.2-p318...
Removing /usr/local/rvm/rubies/ruby-1.9.2-p318...
Removing default ruby interpreter
Removing ruby-1.9.2-p318 aliases...
Removing ruby-1.9.2-p318 wrappers...
Removing ruby-1.9.2-p318 environments...
Removing ruby-1.9.2-p318 binaries...
Installing Ruby from source to: /usr/local/rvm/rubies/ruby-1.9.2-p318, this may take a while depending on your cpu(s)...
ruby-1.9.2-p318 - #fetching 
ruby-1.9.2-p318 - #extracting ruby-1.9.2-p318 to /usr/local/rvm/src/ruby-1.9.2-p318
ruby-1.9.2-p318 - #extracted to /usr/local/rvm/src/ruby-1.9.2-p318
ruby-1.9.2-p318 - #configuring 
ruby-1.9.2-p318 - #compiling 
ruby-1.9.2-p318 - #installing 
Removing old Rubygems files...
Installing rubygems-1.8.18 for ruby-1.9.2-p318 ...
Installation of rubygems completed successfully.
ruby-1.9.2-p318 - adjusting #shebangs for (gem irb erb ri rdoc testrb rake).
ruby-1.9.2-p318 - #importing default gemsets (/usr/local/rvm/gemsets/)
Install of ruby-1.9.2-p318 - #complete

And finally it works:

$ script/rails c
DEPRECATION WARNING: railtie_name is deprecated and has no effect. (called from <top (required)> at /home/israel/proyectos/d-Formacion/config/application.rb:7)
/usr/local/rvm/gems/ruby-1.9.2-p318/gems/actionpack-3.0.4/lib/action_dispatch/http/mime_type.rb:98: warning: already initialized constant PDF
Loading development environment (Rails 3.0.4)
1.9.2-p318 :001 > exit

Why does Rails console say cannot load such file -- readline ?

You need to have the readline libraries installed when you compile Ruby.

If you are on CentOS/Redhat/Fedora Linux, install the package using:

sudo yum install readline-devel

Or, on Ubuntu, use:

sudo apt-get install libreadline6 libreadline6-dev

and then recompile Ruby.

rails console doesn't load due to libreadline

Ran across this today, to solve it I did:

brew rm -f readline

brew install readline

brew link readline --force

Hope it helps.

EDIT: I recently ran into this problem again (after downgrading Ruby) since I wrote this, and I now prefer @califrench's solution from the comments below:

ln -s /usr/local/opt/readline/lib/libreadline.dylib /usr/local/opt/readline/lib/libreadline.7.dylib