Ask Ubuntu is a question and answer site for Ubuntu users and developers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I tried installing rails according to this guide, and when I do, I get this error:

$ sudo gem install rails
  WARNING:  Error fetching data: Errno::ENOENT: No such file or directory - getaddrinfo (
  WARNING:  Error fetching data: Errno::ENOENT: No such file or directory - getaddrinfo (
  Building native extensions.  This could take a while...
  ERROR:  Error installing rails:
      ERROR: Failed to build gem native extension.

          /usr/bin/ruby1.9.1 extconf.rb
  /usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require': cannot load such file -- mkmf (LoadError)
      from /usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
      from extconf.rb:1:in `<main>'

  Gem files will remain installed in /var/lib/gems/1.9.1/gems/json-1.8.0 for inspection.
  Results logged to /var/lib/gems/1.9.1/gems/json-  1.8.0/ext/json/ext/generator/gem_make.out

I've never seen anything like this before, so any feedback would be greatly appreciated.

share|improve this question

Try to re-install Ruby, then Gem and then install Rails. Problem maybe is on Ruby or Gem.

share|improve this answer

try to use rvm or rbenv they both works great .. i personally prefer rvm because i want to keep gem-sets separate for different projects . see if you want to simple installation just using one ruby version then go for rbenv Rbenv Installation instruction ( my blog post )

  1. Installing rbenv


    sudo apt-get update
    sudo apt-get upgrade -y

    Install required components for Ruby and other dependencies.

    sudo apt-get install git-core -y
    sudo apt-get install curl -y
    sudo apt-get install build-essential openssl libreadline6 libreadline6-dev curl git-core zlib1g zlib1g-dev libssl-dev libyaml-dev libsqlite3-dev sqlite3 libxml2-dev libxslt-dev autoconf libc6-dev libgdbm-dev ncurses-dev automake libtool bison subversion pkg-config libffi-dev
    git clone git:// ~/.rbenv
    echo ‘export PATH="$HOME/.rbenv/bin:$PATH"’ >> ~/.profile
    echo ‘eval "$(rbenv init -)"’ >> ~/.profile

    (Note: modify .bash_profile , .bash_login or .zshrc according to your needs.)

    Now install some required rbenv plugins.

    cd  ~/.rbenv/
    mkdir plugins
    cd  ~/.rbenv/plugins
    git clone git://

    Restart the terminal.

  2. Installing Ruby

    rbenv  install 1.9.3-p385

    Set your global Ruby version.

    rbenv global 1.9.3-p385
    rbenv rehash
    ruby -v
  3. Install Ruby on Rails Framework

    gem install bundler
    gem install rails

    (Don't panic, installing rails will take some time.)

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.