Anyone Care to Critique my Apt Preferences? (was Re: apt-cacher as package rollback buffer)

[Freeman <evenso@worldwidehtml.com>]

On Mon, Feb 15, 2010 at 05:10:26PM -0800, evenso wrote:
> On Mon, Feb 15, 2010 at 02:33:05PM -0600, Boyd Stephen Smith Jr. wrote:
> > On Monday 15 February 2010 13:30:19 Freeman wrote:
> 
> > 
> > > However, could a rollback represent an incursion on the priority system?
> > 
> > With testing/unstable/experimental, you'll have your Default-Release set to 
> > testing so that package versions in testing get priority 990, package versions 
> > in unstable get priority 500, and package versions in experimental get 
> > priority 1.
> > 
> > 0. If there is a versioned dependency apt-get / aptitude will satisfy it; it 
> > will not take into consideration versions that do not satisfy the dependency.
> > 
> > 1. If the version you have installed is less than the version in testing apt-
> > get / aptitude will want to upgrade it to the testing version.
> > 
> > 2. If the version you have installed is greater than the version in testing, 
> > but less than the version in unstable, apt-get / aptitude will want to upgrade 
> > it to the unstable version.
> > 
> > 3. If the version you have installed is greater than the version in unstable, 
> > apt-get / aptitude will not want to upgrade it.
> > 
> > You can use individual package pins to alter this.  Pinning your currently 
> > installed version to (501-)990 would prevent 2 above, but not 1.  Pinning your 
> > currently installed version to 991(-999) would prevent both 1 and 2 above.  
> > Pinning your currently installed version to 1 would cause 3 above to upgrade 
> > your package to experimental instead.
> > 
> 
> I decided on a preferences file for caution and for future developments. Thus far:
> 
> |Package: *
> |Pin: release a=testing
> |Pin-Priority: 990
> |
> |Package: *
> |Pin: release a=unstable
> |Pin-Priority: 700
> |
> |Package: *
> |Pin: release a=experimental
> |Pin-Priority: 500
> |
> |Package: *
> |Pin: release a=lenny/volatile
> |Pin-Priority: 300
> |
> |Package: *
> |Pin: release a=stable
> |Pin-Priority: 100
> 
> 
> To rollback a package to a previous version existing only in my apt-cacher
> archive:
> 

(Contingency)

> |Package: < package_name >
> |Pin: version < nnn* >
> |Pin-Priority: 1001
> 

The above preferences are for testing/unstable/experimental with a
contingency for and emergency rollback a package to an obsolete package
archived in my apt-cacher files. (My recent experience with the buggy
xserver-xorg/mesa upgrade prompted this plan.)

I'd rather find out that the above Preferences are destructive here than
during an install!

My ego may be the more delicately balanced but my system is the more
precious. :)

-- 
Kind Regards,
Freeman