Package for Ruby 2.0 on precise

You could use the following PPA:

sudo add-apt-repository ppa:brightbox/ruby-ng-experimental
sudo apt-get update
sudo apt-get install -y ruby2.0 ruby2.0-dev ruby2.0-doc

Optional:

sudo apt-get install -y mysql-server mysql-workbench
sudo gem install rails

Now you can go ahead and download your preferred IDE and start having fun with Ruby 2.0 and Rails 4.

Just so you know, I find this one here very cool: http://www.jetbrains.com/ruby/

Note: you can use any other database and IDE, these are just my personal preferences.

Ubuntu has Stable Release Updates Policy which basically disallow importing new versions into stable releases. So it's not possible to have official Ruby 2.0 packages in the Ubuntu 12.04, because it could introduce new bugs, regressions, etc. So you will have to rely on some future-to-be PPA.

Just to clarify whole process, how does a package enter Ubuntu. Because Ruby 2.0 is not even packaged yet.

The usual release process of Ubuntu is to wait for packages to appear in Debian first and import them from there.

That said the Debian is frozen right now and next stable release should be released soon, so not much progress is happening. But... there's already ITP (Intent to Package) bug for ruby2.0, which means that Ruby packagers are already working on that. You can track the progress in the git://anonscm.debian.org/collab-maint/ruby2.0.git repository, and even help.

The sooner the ruby2.0 appears in Debian, the sooner it will be in next Ubuntu, but it won't be backported automatically to already released versions of Ubuntu.

You can easily build the latest version yourself:

Simply go to http://cache.ruby-lang.org/pub/ruby/ and identify the version you'd like to install in .tar.gz format. Then install via console:

sudo apt-get -y update
sudo apt-get -y install build-essential zlib1g-dev libssl-dev libreadline6-dev libyaml-dev
cd /tmp
wget http://cache.ruby-lang.org/pub/ruby/2.1/ruby-2.1.1.tar.gz
tar -xvzf ruby-2.1.1.tar.gz
cd ruby-2.0.0-p353/
./configure --prefix=/usr/local
make
sudo make install

This example installs ruby 2.1.1, simply replace the URI after the wget command with your preferred version.

The developers have not commented on this to the extent of my knowledge but since the release date of ruby 1.9.3 was october 2011 and to this day 1.9.3 is still not in 11.10, I would say it is unlikely that new rubies will be added after release of the system. A quick look at packages.ubuntu.com shows that the developers have a history of not adding rubies to ubuntu that are released after ubuntu is released. That being said, there are other ways to install ruby 2.0 if you need such as installing from source, rvm, or ruby-build (with or without rbenv or chruby). I use ruby 2.0 on my system that I installed using ruby-build and rbenv and have had no issues so far. Based on past history I would say it is unlikely the developers will add ruby 2.0 to the official 12.04 or even 12.10 repositories, however this does not mean it will for sure not happen. 2.0 has yet to be included in the 13.04 repositories either so it is possible it is just tested thoroughly enough by the developers and it could still be added. I would not count on that though.