Re: Pin, Pin-Priority, and Tracking

[dman <dsh8290@rit.edu>]

On Tue, Feb 19, 2002 at 11:42:42PM -0800, Paul E Condon,,, wrote:
| I recently dist-upgraded to Woody, using a script by Osamu Aoki. It took 
| many hours over ppp,
| but it worked. Thanks, Osamu!
| 
| And he is right in saying the install of Woody is too easy. Beyond 
| stumbling onto his post telling about his script very little was 
| required of me. But now a question:
| 
| Part of the upgrade was, of course, upgrading apt-get and dpkg. The 
| script installed a file
| /etc/apt/preferences which had not been there before and gave some brief 
| instructions about
| something called "tracking". I'm guessing this new stuff has something 
| to do with keeping
| track of stable, testing, and unstable all at once. What does this stuff 
| really do? How does it
| work? Where do I look to find out?

Look at Osamu's web page.  He explained it to me there.

Basically here's how it works : you include all of potato, woody, and
sid (or whatever subset may be interesting to you) in your
sources.list file.  This will give you a complete database of
available packages.  Then each package gets a priority based on
several criteria.  First, currently installed packages get a priority
of 100.  For not currently installed packages, the preferences file is
consulted to see if a package is given a priority.  My preferences
file looks like this :

Package: *
Pin: release a=testing
Pin-Priority: 900

Package: *
Pin: release a=stable
Pin-Priority: 500

Package: *
Pin: release a=unstable
Pin-Priority: 95

If the package in question is found in testing and its name matches
"*", then it has a priority of 900.  This is higher than a currently
installed package, so if a new version is in testing it will get
installed (via 'apt-get upgrade').  If a package is found in stable it
has a priority of 500.  If the version is newer, then it will be
installed.  However, unstable has a priority of 95.  This is less than
that of an installed package.  Thus a package in sid will never be
preferred over an installed package regardless of version.  If it
doesn't exist anywhere else, then it will have priority.  With this
setup, I am "tracking" woody (and potato, but not really).  When woody
changes, my system will change to "track" that.

-D

-- 

In the way of righteousness there is life;
along that path is immortality.
        Proverbs 12:28