Get the latest tech news
Observations in Debian Dependency Solving
In my previous blog, I explored The New APT 3.0 solver. Since then I have been at work in the test suite making tests pass and fixing some bugs. You see for all intents and purposes, the new solver is a very stupid naive DPLL SAT solver (it just so happens we don’t actually have any pure literals in there). We can control it in a bunch of ways: We can mark packages as “install” or “reject” We can order actions/clauses.
Should we follow currently satisified Suggests so the solver sees them and doesn’t autoremove them, but treat them as optional? (1) It means if we show you why A could not be installed, you don’t even see A (= 3) in the list of choices and (2) you would need to keep the pkgDepCache around for the temporary overrides. This doesn’t really increase the search space either but it solves both our problem of making overrides work and giving you a reasonable error message that lists all versions of A.
Or read this on Hacker News