motu-release will revert libgems-ruby to the old state.

[Mathias Gug]

Hi Loïc,

On Mon, Sep 01, 2008 at 07:17:29PM +0200, Loïc Minier wrote:
> On Mon, Sep 01, 2008, Mathias Gug wrote:
> >   1. sudo apt-get install rubygems
> >   2. sudo gem install rails
> >   3. Modify the default PATH in the environment to include
> >   /var/lib/gems/1.X/bin/ so that the rails command can be invoked from the
> >   command line.
> >   The upload aims at removing step number 3 from the process by symlinking
> >   the gem binary from /var/lib/gems/1.X/bin/ into /usr/local/bin/.
> 
>  -You certainly considered the following option, but I'm curious about
>  the rationale for excluding it from the implementation.)
> 
>  Why don't you do 3 in place of the admin instead of using /usr/local?
> 
>  If touching /etc/environment is too fragile, could we add some new
>  mechanism to handle default PATH changes (e.g. /etc/environment.d)?
> 
>  For example, libnssmdns mangles /etc/nsswitch.conf to add its entries:
>  this sounds equally intrusive to me.
> 

This was indeed suggested at the very beginning of the bug thread [1] by
using /etc/profile.d/. However it was rejected on the following grounds
[2]:

base-files (4.0.1ubuntu2) hardy; urgency=low

  * Implement LSB-3.1, 16.2 (/etc/profile.d). Addresses LP #102105.
    According to Debian policy 9.9 (Environment variables), programs
    installed by packages must not depend on environment variables
    to get reasonable defaults. Do not use this LSB feature to
    set or modify environment variables.

  -- Matthias Klose <doko at ubuntu.com> Wed, 06 Feb 2008 15:27:17 +0100

This is related to section 9.9 of the Debian Policy [3], Environment variables:

  A program must not depend on environment variables to get reasonable
  defaults. (That's because these environment variables would have to be
  set in a system-wide configuration file like /etc/profile, which is not
  supported by all shells.) 

Colin Watson gave other reasons in bug 18808 [4] related to this issue.

[1]: https://bugs.launchpad.net/ubuntu/+source/libgems-ruby/+bug/145267/comments/7
[2]: https://bugs.launchpad.net/ubuntu/+source/libgems-ruby/+bug/145267/comments/11
[3]: http://www.debian.org/doc/debian-policy/ch-opersys.html#s9.9
[4]: https://bugs.launchpad.net/ubuntu/+source/base-files/+bug/18808/comments/1

-- 
Mathias Gug
Ubuntu Developer  http://www.ubuntu.com