Installing Ruby 1.9.1 on Ubuntu?

Save yourself the headache and use RVM (Ruby Version Manager)

Keep in mind, Rails 3 works best with Ruby 1.9.2. Ruby 1.9.2 fixes up quite a few bugs in 1.9.1 and is preferable to running 1.9.1.

With RVM installing 1.9.2 is a breeze.

sudo apt-get install ruby1.9.1-full

(http://www.ruby-lang.org/en/downloads/)

After running

sudo apt-get install ruby1.9.1-full

It's solution is to run the following command:

sudo update-alternatives --config ruby

Then you will get this output:

   There are 2 choices for the alternative ruby (providing /usr/bin/ruby).     Selection    Path                Priority   Status   ------------------------------------------------------------   * 0            /usr/bin/ruby1.8     50        auto mode     1            /usr/bin/ruby1.8     50        manual mode     2            /usr/bin/ruby1.9.1   10        manual mode   Press enter to keep the current choice[*], or type selection number: 2   update-alternatives: using /usr/bin/ruby1.9.1 to provide /usr/bin/ruby (ruby) in    manual mode.   $ ruby --version   ruby 1.9.2p290 (2011-07-09 revision 32553) [x86_64-linux]

Credit for this solution goes to person who answered https://askubuntu.com/questions/91693/how-do-you-uninstall-ruby-1-8-7-and-install-ruby-1-9-2 . Currently the ruby1.9.1 package is actually ruby 1.9.2.