Ruby 1.9.2 and Rails 3 cannot open rails console

Question

[gkaykck@main myApplication]$ rails console
/usr/local/lib/ruby/1.9.1/irb/completion.rb:9:in `require': no such file to load -- readline (LoadError)
    from /usr/local/lib/ruby/1.9.1/irb/completion.rb:9:in `<top (required)>'
    from /usr/local/lib/ruby/gems/1.9.1/gems/railties-3.0.3/lib/rails/commands/console.rb:3:in `require'
    from /usr/local/lib/ruby/gems/1.9.1/gems/railties-3.0.3/lib/rails/commands/console.rb:3:in `<top (required)>'
    from /usr/local/lib/ruby/gems/1.9.1/gems/railties-3.0.3/lib/rails/commands.rb:20:in `require'
    from /usr/local/lib/ruby/gems/1.9.1/gems/railties-3.0.3/lib/rails/commands.rb:20:in `<top (required)>'
    from script/rails:6:in `require'
    from script/rails:6:in `<main>'

I have installed rails 3 on ruby 1.9.2p136, which is ok i guess. But i cannot start rails console and it gives me the error i copied. The apps worked great with ruby 1.8.7 and i never saw an error like this.

Any ideas what it could be?

Answer 1

Apparently ubuntu and ruby don't always catch dependencies like they should.

From the first google hit (yeah, I clicked on this stack-overflow in place #2 before checking out the first result.)

Navigate to the Ruby source and enter:

sudo apt-get install libreadline5-dev
cd ext/readline
ruby extconf.rb
make
sudo make install

So, if you're on another distro, make sure you install readline somehow (source/package), then run make/install on extconf from the source. I tried what gkaykck suggested of course but got this without readline already on my system.

$ ruby extconf.rb
checking for tgetnum() in -lncurses... no
checking for tgetnum() in -ltermcap... no
checking for tgetnum() in -lcurses... no
checking for readline/readline.h... no
checking for editline/readline.h... no

Answer 2

Recipe for those who use rvm:

rvm pkg install readline
rvm remove 1.9.3
rvm install 1.9.3 --with-readline-dir=$rvm_path/usr

In more details about it on https://rvm.io/packages/readline/

Answer 3

If you want another solution to this problem do this.

sudo apt-get install libreadline6

Then in your gem file add:

gem 'rb-readline'

Then

bundle install

And you should be all set.

Answer 4

I'd recommend using rvm (Ruby Version Manager) to manage your different versions of Ruby and switch between them. It does a pretty good job of compiling the various versions for you too. You can even create per-directory .rvmrc files to tell rvm what version of ruby to use in which directory (as well as use per-project gem sets if you want!)

Answer 5

First of all uninstall every ruby version you have.

After that display rvm requirements:

rvm requirements

You will get something like:

Requirements for Linux ( DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=11.10
DISTRIB_CODENAME=oneiric
DISTRIB_DESCRIPTION="Ubuntu 11.10" )

NOTE: 'ruby' represents Matz's Ruby Interpreter (MRI) (1.8.X, 1.9.X)   
This is the *original* / standard Ruby Language Interpreter  
      'ree'  represents Ruby Enterprise Edition  
      'rbx'  represents Rubinius  

bash >= 4.1 required curl is required git is required (>= 1.7 for
ruby-head) patch is required (for 1.8 rubies and some ruby-head's).

To install rbx and/or Ruby 1.9 head (MRI) (eg. 1.9.2-head), then you
must install and use rvm 1.8.7 first.

Additional Dependencies: 
# For Ruby / Ruby HEAD (MRI, Rubinius, & REE), install the following:
  ruby: /usr/bin/apt-get install build-essential openssl libreadline6 
  libreadline6-dev curl git-core zlib1g zlib1g-dev libssl-dev libyaml-dev 
  libsqlite3-0 libsqlite3-dev sqlite3 libxml2-dev libxslt-dev autoconf libc6-dev 
  ncurses-dev automake libtool bison subversion

# For JRuby, install the following:
  jruby: /usr/bin/apt-get install curl g++ openjdk-6-jre-headless
  jruby-head: /usr/bin/apt-get install ant openjdk-6-jdk

# For IronRuby, install the following:
  ironruby: /usr/bin/apt-get install curl mono-2.0-devel

Install all dependencies via apt-get.
After that install ruby 1.8.7. This version is required if you plan to use ruby 1.9.x
Now you can install ruby 1.9.3:

rvm pkg install readline
rvm remove 1.9.3
rvm install 1.9.3 --with-readline-dir=$rvm_path/usr

Note that you dont even need to install readline package via rvm if you had installed it using apt-get.

Answer 6

With CentOS 6:

Remember we are working from the ruby install dir, for me it was:

  /opt/ruby-1.9.3-p194/ext/readline 

If you see the following output, then readline is not installed:

$ ruby extconf.rb 
checking for tgetnum() in -lncurses... no
checking for tgetnum() in -ltermcap... no
checking for tgetnum() in -lcurses... no
checking for readline/readline.h... no
checking for editline/readline.h... no

To install with RPM:

yum install readline-devel

Then build it:

ruby extconf.rb 
make
sudo make install

Answer 7

Adding in the Gemfile

gem 'rb-readline'

and then bundle install

did the trick for me

Answer 8

Solution is to go to the source folder you compiled ruby => ext => readline than

ruby extconf.rb
make
sudo make install

Answer 9

If you're using RVM you can re-make readline. This fixed the issue for me. Instructions here:

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

Answer 10

use rvm remove to remove all ruby installed. do a "which ruby" if you still get something, you need to reinstall rvm then install ruby using rvm.