How to use gem to install Rails on Ubuntu

After upgrading to Rails 4.2.4 on Ubuntu 14.04 using RVM I needed to do this:

sudo apt-get install libgmp-dev

or

sudo apt-get install libgmp3-dev

Full stacktrace: http://ruby-on-rails-eq8.blogspot.co.uk/2015/10/solving-ubuntu-1404-ruby-c-dependancy.html

You seem to be missing some Ruby requirement. If you are using RVM, try:

rvm requirements

to get the list of dependencies and install them manually.

Otherwise, install the known basic requirements directly using:

sudo apt-get install build-essential bison openssl libreadline6 libreadline6-dev curl git-core zlib1g zlib1g-dev libssl-dev libyaml-dev libxml2-dev autoconf libc6-dev ncurses-dev automake libtool

You get this error because the development dependencies for Ruby are missing.

I suggest that you install and use RVM to solve this, check the official and updated instructions here https://rvm.io/rvm/install

At the time when I answer this question I followed these steps:

gpg --keyserver hkp://keys.gnupg.net --recv-keys409B6B1796C275462A1703113804BB82D39DC0E3\curl -sSL https://get.rvm.io | bash

If you get this warning

  * WARNING: You have '~/.profile' file, you might want to load it,    to do that add the following line to '/home/mao/.bash_profile':  source ~/.profile

execute this command:

echo source ~/.profile >> ~/.bash_profile

Then, reload/apply the bash_profile that you just updated by executing this:

source ~/.bash_profile

Finally run this to install the requirements:

rvm requirements

This should work for any Linux distribution like Ubuntu, Fedora, Debian, Redhat, Slackware.