Changes to Ruby in Debian (and Ubuntu)

May 27th, 2011 by lucas

(this is a copy of an mail sent to ruby-core@ and ruby-talk@)

Since the beginning of 2011, the Debian Ruby team has been working on several big changes. Those changes all are available in Debian unstable, some of them are also available in Debian testing, and they should all be available in the next Debian and Ubuntu releases.

I think that it addresses most of the reasonable concerns about Ruby in Debian.

Using alternatives to switch between Ruby implementations

The alternatives system is now used to manage the “ruby” symlink and the other related symlinks, making it easy to switch between Ruby implementations (only Ruby 1.8 and 1.9.X at the moment) (see this mail for details). The default choice for Ruby is still 1.8, but this change will make it easy for us to make a switch to 1.9.X by default (likely by the release of Debian wheezy).

Installing gems executables to /usr/local/bin

Rubygems (both as a standalone package, and as shipped with Ruby 1.9.X) now install executables to /usr/local/bin. (The other files still get installed under /var, see this mail)

Enabling gem update –system

gem update –system has been re-enabled. Since upgrading rubygems to a version that may not have been properly tested with the rest of the Debian system may cause issues in the user’s system, there’s a big warning about that. The user can confirm and upgrade rubygems anyway by defining an environment variable.

New gem2deb packaging helper

There’s a new packaging helper, named gem2deb, that makes it very easy to generate Debian source packages from Rubygems. We are in the process of migrating all ruby libraries packaged in Debian to that new helper. It will take some time, though (help is welcomed).

Transition status: http://pkg-ruby-extras.alioth.debian.org/wheezy/

One big benefit of the switch to gem2deb for the Ruby community is that, in the process, we are enabling test suites at build time for each package and each Ruby implementation. This should make it easy to detect regressions in new interpreter versions.

Ruby 1.9.3

We will switch to Ruby 1.9.3 ASAP (probably when it is branched off trunk, with a package first in Debian experimental). Since the Ruby compatibility version issue is likely to stay around, we will re-evaluate how we are dealing with it (to avoid the ruby1.9.1 package <=> ruby -v = 1.9.2 problem that confuses many users). This is likely by switching the package name to ruby1.9.3 (keep a ruby1.9.1 package for compatibility). The package containing the shared library will stay libruby1.9.1.

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6 Responses to “Changes to Ruby in Debian (and Ubuntu)”

  1. Elessar wrote on 05/27/11 at 11:55 am :

    Why using the alternative system? It is designed to allow switching between implementations of an interface. Different versions of Ruby are not made to be implementations of an interface, I think.

    If someone wants to use Ruby 1.9, all he has to do is to run ruby1.9, what is this strange use of the alternative system for?

  2. lucas wrote on 05/27/11 at 12:09 pm :

    > Different versions of Ruby are not made to be implementations of an interface, I think.

    I think they are.

  3. Elessar wrote on 05/27/11 at 1:17 pm :

    > I think they are.

    You are the one that know it best, but I think it deserved this little explanation, because this was not obvious, at least to me. The Ruby world has some specificities compared to others such a Python, I think. Thank you for your work and good luck.

  4. Yannick wrote on 05/27/11 at 10:47 pm :

    Hi Lucas,

    It would be cool if gem could be configure to work on a user specified directory (in Home dir for instance) using –install-dir.

    I recently came into Haskell’s cabal (from cabal-install) that makes it easy to do this to locally install Haskell programmes.

    But maybe it’s more an upstream problem.

    Yannick

  5. Victor Costan wrote on 05/28/11 at 3:22 pm :

    Dear Lucas,

    Thank you so much! These changes address the issues I had with the Ruby packages in Debian / Ubuntu. I’m really looking forward to being able to switch to 1.9.2 / 1.9.3 via alternatives.

    Thank you for making my life easier!

    Victor

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