[Aptitude-devel] Development update

[Daniel Burrows]

  So, over the last few days I've quietly caught up to where I was when
I lost my previous laptop, and gone a bit further.  This means that
*A PROTOTYPE OF THE NEW COST SYSTEM IS AVAILABLE* in head.  The default
behavior should be 100% exactly the same as in 0.6.1.5-3, and it should
be considered a bug if you see a divergence.  To get different behavior,
modify the configuration parameter

    Aptitude::ProblemResolver::SolutionCost

  to a string like

    "safety, removals + canceled-actions, priority"

  and see whether aptitude really minimizes, in this case, the sum of
the number of removals and the number of canceled actions.  "safety" is
the old tiering system, so

    "safety, priority"

  should give you the behavior of 0.6.1.5-3 (and is thus the default).

  Still to come: being able to discard solutions if a particular
cost entry gets too large (e.g., letting the user request no more than
10 removals -- mostly useful for making safe-upgrade not necessarily a
special case).  Also, documentation and unit tests that don't fail with
a message saying "implement this unit test".

  Daniel