[Aptitude-devel] Bug#608786: "priority" cost level is broken which makes it basically useless

[Daniel Hartwig]

tags 608786 + pending
thanks

Modestas Vainius <modax at debian.org> wrote:
>
> while documentation [1] says the following:
>
> priority  Level   A value that increases as the apt pin priority of a version
>                   decreases. Specifically, this is computed by negating the pin
>                   priority (so, e.g., if the pin priority is 500, this
>                   component will compute -500).
>
> code does not reflect this. In particular, priority is NOT negated and included
> as is in the cost calculation. This bug basically makes priority cost level a
> no-op and useless. The one-line patch against 0.6.3 is attached.

Hello

This appears to be quite an oversight.  I note that there was previous
code that did negate the priority cost, but it has since been replaced
by the current, buggy version.

# ./aptitude --log-resolver \
 -oAptitude::ProblemResolver::SolutionCost=priority install apt/experimental
…
INFO aptitude.resolver.search - --- Returning the future solution
…;C(nop, advance: 1)S-1938 from step 50
INFO aptitude.resolver.search - --- Returning the future solution
…;C(nop, advance: 500)S-9940 from step 2
…

With this patch I get those same solutions in the correct (priority)
order:

# ./aptitude --log-resolver \
 -oAptitude::ProblemResolver::SolutionCost=priority install apt/experimental
…
INFO aptitude.resolver.search - --- Returning the future solution
…;C(nop, advance: -500)S-9940 from step 2
INFO aptitude.resolver.search - --- Returning the future solution
…;C(nop, advance: -1)S-1938 from step 50
…

I have applied the patch to the Git repository.

Thanks for the report!