Re: Changes for Ruby in Debian (and Ubuntu)

[Lucas Nussbaum <lucas@lucas-nussbaum.net>]

On 24/05/11 at 16:11 -0700, brettg wrote:
> On 05/24/2011 02:26 PM, Lucas Nussbaum wrote:
> >  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). 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).
> >
> 
> 
> How is this being managed, I only review debian-ruby a few times a
> month to see major changes and I hadn't noticed this.

*** lucas@beothuk:~$ sudo update-alternatives --display ruby
ruby - auto mode
  link currently points to /usr/bin/ruby1.8
/usr/bin/ruby1.8 - priority 50
  slave erb: /usr/bin/erb1.8
  slave erb.1.gz: /usr/share/man/man1/erb1.8.1.gz
  slave irb: /usr/bin/irb1.8
  slave irb.1.gz: /usr/share/man/man1/irb1.8.1.gz
  slave rdoc: /usr/bin/rdoc1.8
  slave rdoc.1.gz: /usr/share/man/man1/rdoc1.8.1.gz
  slave ri: /usr/bin/ri1.8
  slave ri.1.gz: /usr/share/man/man1/ri1.8.1.gz
  slave ruby.1.gz: /usr/share/man/man1/ruby1.8.1.gz
  slave testrb: /usr/bin/testrb1.8
  slave testrb.1.gz: /usr/share/man/man1/testrb1.8.1.gz
/usr/bin/ruby1.9.1 - priority 10
  slave erb: /usr/bin/erb1.9.1
  slave erb.1.gz: /usr/share/man/man1/erb1.9.1.1.gz
  slave irb: /usr/bin/irb1.9.1
  slave irb.1.gz: /usr/share/man/man1/irb1.9.1.1.gz
  slave rdoc: /usr/bin/rdoc1.9.1
  slave rdoc.1.gz: /usr/share/man/man1/rdoc1.9.1.1.gz
  slave ri: /usr/bin/ri1.9.1
  slave ri.1.gz: /usr/share/man/man1/ri1.9.1.1.gz
  slave ruby.1.gz: /usr/share/man/man1/ruby1.9.1.1.gz
  slave testrb: /usr/bin/testrb1.9.1
  slave testrb.1.gz: /usr/share/man/man1/testrb1.9.1.1.gz
Current 'best' version is '/usr/bin/ruby1.8'.
*** lucas@beothuk:~$ sudo update-alternatives --set ruby /usr/bin/ruby1.9.1
update-alternatives: using /usr/bin/ruby1.9.1 to provide /usr/bin/ruby (ruby) in manual mode.
*** lucas@beothuk:~$ ruby --version
ruby 1.9.2p180 (2011-02-18 revision 30909) [x86_64-linux]
*** lucas@beothuk:~$ sudo update-alternatives --set ruby /usr/bin/ruby1.8
update-alternatives: using /usr/bin/ruby1.8 to provide /usr/bin/ruby (ruby) in manual mode.
*** lucas@beothuk:~$ ruby --version
ruby 1.8.7 (2011-02-18 patchlevel 334) [x86_64-linux]


Rubygems has its own alternatives set:
*** lucas@beothuk:~$ sudo update-alternatives --display gem
gem - auto mode
  link currently points to /usr/bin/gem1.8
/usr/bin/gem1.8 - priority 180
  slave bash_completion_gem: /etc/bash_completion.d/gem1.8
  slave gem.1.gz: /usr/share/man/man1/gem1.8.1.gz
/usr/bin/gem1.9.1 - priority 10
  slave bash_completion_gem: /etc/bash_completion.d/gem1.9.1
  slave gem.1.gz: /usr/share/man/man1/gem1.9.1.1.gz
Current 'best' version is '/usr/bin/gem1.8'.

That's because it's not possible to have alternatives that span over different
packages, unfortunately.

- Lucas