Re: Aptitude Error
- To: email@example.com
- Subject: Re: Aptitude Error
- From: Daniel Burrows <firstname.lastname@example.org>
- Date: Fri, 30 Apr 2010 21:07:33 -0700
- Message-id: <20100501040733.GF26444@emurlahn.burrows.local>
- In-reply-to: <20100501035819.GD26444@emurlahn.burrows.local>
- References: <email@example.com> <firstname.lastname@example.org> <email@example.com> <firstname.lastname@example.org> <20100501035819.GD26444@emurlahn.burrows.local>
On Fri, Apr 30, 2010 at 08:58:19PM -0700, Daniel Burrows <email@example.com> was heard to say:
> On Fri, Apr 30, 2010 at 12:54:57PM -0500, "Boyd Stephen Smith Jr." <firstname.lastname@example.org> was heard to say:
> > My instinct is that '-t $something' effectively increases the priority of all
> > packages from the $something repository, which may make the dependency
> > resolver pull more from that repository than is absolutely necessary.
> If you pass "-t ARCHIVE", that means that versions from ARCHIVE are
> treated as the default package version. It also increases the pin
> priority to 990. aptitude's resolver tries particularly hard to install
> the default package version, and it will tie-break using the priority
> (you can configure both those behaviors extensively, but those are the
> defaults). The story is more extreme with the apt resolver: it won't
> even consider anything but the default version of a package.
That's not quite right.
The default version is the highest-priority available version. It
just happens that setting the pin priority to 990 *normally* has the
effect of changing the default version, but you could theoretically
manually pin another version to be higher.
The second effect of Default-Release is to change how certain
aptitude / apt-get commands choose the target version. This includes
"apt-get source", "apt-get build-dep", "aptitude build-dep", "aptitude
changelog", "aptitude download", and "aptitude show". In aptitude,
it causes arguments with no archive or version specifier to be treated
as if "/default-release" had been included. Unfortunately, it's
dreadfully underdocumented and underspecified.