Debians commandline package manager https://git.kalnischkies.de/apt/atom?h=main 2026-01-31T16:30:20Z 2026-01-31T16:30:20Z Julian Andres Klode jak@debian.org 2025-12-29T17:47:15Z urn:sha1:1fbb857b6b2cbddcea9e8b03aa0c766c72e91f34 Instead of tracking dependencies and reverse dependencies, install classical watchers. This vastly streamlines the propagation code and allows us to easily switch to literals in the next step. This implementation watches _all_ solutions rather than using the modern 2-watched literals scheme or the intermediate head/tail watchers. Ultimately a more effective watcher scheme would be interesting but not a significant priority seeing as most of the solver runtime is spent not in propagation but in problem translation. decision trees -------------- The new watchers produce slightly different decision trees, sometimes subtly changing solutions. Notably in various observed examples in Ubuntu 25.04, courier was installed as an MTA instead of postfix: The old decision tree was: apcupsd:amd64 -> mailutils:amd64=1:3.18-1 -> mailutils:amd64 -> postfix:amd64=3.9.1-10ubuntu1 The new decision tree is: lsb:amd64 -> lsb-core:amd64 -> courier-mta:amd64=1.3.13-1 The difference here being that lsb-core declares a mail-transport-agent dependency whereas mailutils depends on `default-mta | mail-transport-agency`; but both are effectively subject to selection at similar time. Further work is needed to optimize selection. A notable choice may also be to deal with broken packages like lsb-core that declare dependencies solely on a virtual package by reconstructing the default provider for that package utilizing default-* dependencies or similar notions. Likewise in the test suite, explanations are different in some uninstallable cases. backtracking ~~~~~~~~~~~~ The following major changes were observed in the 25.04 test suite: -tmp/regression-remove/07f0a068-36c2-11f0-b7c1-fa163e171f02:18 +tmp/regression-remove/07f0a068-36c2-11f0-b7c1-fa163e171f02:3 -tmp/regression-remove/32078f70-3734-11f0-a75a-fa163ec8ca8c:64 +tmp/regression-remove/32078f70-3734-11f0-a75a-fa163ec8ca8c:19 Other test cases showed little deviation, +/- 1, generally the same amount of backtracking. performance ~~~~~~~~~~~ Running Ubuntu's regression test suite resulted in no significant performance difference being observable. Before: 290s user time; 16.66% solver After: 299s user time; 17.36% solver Tests where run with make -j 8 and solver performance extracted perf report --symbol-filter=ResolveExternal --stdio 2026-01-05T21:20:24Z Julian Andres Klode jak@debian.org 2025-12-28T15:56:28Z urn:sha1:21d099878ed8c34f3b13747bcec380e0402e57a3 The previous use of decision here conflicted with the use of decision level and the general notion of having made a decision, because the assignment might have been propagated as a matter of fact. 2025-03-08T22:18:05Z Julian Andres Klode julian.klode@canonical.com 2025-03-06T19:07:30Z urn:sha1:3967b75ae4a10d0d79560dfecb8eb210aad4f4f2 Introduce a new function, LongWhyStr() that returns a longer reason for why something is being installed (or not). This does the same path walk as the other function does, but it renders the clauses at each level, and one per line, so the whole output is a lot more informative. It is a separate function to keep the existing debug messages use the simple single line implication graph We remove the other special case in AddWork() for empty solutions to mke use of the general case in Solve() instead, and then adapt the case in Solve() to the same case as in Enqueue(). This also happens to fix the bug that when we encountered an empty clause we just printed the clause had no solution, but not how we got to install the package with the clause. Adapt the test suite for the changes which is an annoying amount of paperwork. 2025-02-14T18:08:45Z Julian Andres Klode julian.klode@canonical.com 2025-02-11T14:54:46Z urn:sha1:4a98dcf274123190a0ebff2bd223cbc9d11e35f9 This is a bit gnarly, but dist-upgrade is mapped to is an upgrade + removals allowed + installs allowed :D 2021-11-17T16:32:18Z Julian Andres Klode julian.klode@canonical.com 2021-11-17T15:29:09Z urn:sha1:891efe3b201a104445ea723a3a5b9b434a78c364 Suggesting the removal of Essential and Protected packages as a solution leads to situations where YouTubers end up removing their desktop. Let's not remove such packages ourselves. 2015-12-19T22:04:34Z David Kalnischkies david@kalnischkies.de 2015-12-15T16:20:26Z urn:sha1:3abb6a6a1e485b3bc899b64b0a1b7dc2db25a9c2 This doesn't allow all tests to run cleanly, but it at least allows to write tests which could run successfully in such environments. Git-Dch: Ignore 2015-08-10T15:27:17Z David Kalnischkies david@kalnischkies.de 2015-07-12T11:41:12Z urn:sha1:a0c19a217ca2ed38ae0ecb4b8d2d4f8c4e53289f apt-get is displaying various lists of package names, which until now it was building as a string before passing it to ShowList, which inserted linebreaks at fitting points and showed a title if needed, but it never really understood what it was working with. With the help of C++11 the new generic knows not only what it works with, but generates the list on the fly rather than asking for it and potentially discarding parts of the input (= the non-default verbose display). It also doubles as a test for how usable the CacheSets are with C++11. (Not all callers are adapted yet.) Git-Dch: Ignore 2015-03-16T17:01:54Z David Kalnischkies david@kalnischkies.de 2015-03-09T23:59:44Z urn:sha1:25b86db159fbc3c043628e285c0c1ef24dec2c6e We use test{success,failure} now all over the place in the framework, so its only consequencial to do this in the situations in which we test for a specific output as well. Git-Dch: Ignore 2014-09-26T22:10:05Z David Kalnischkies david@kalnischkies.de 2014-08-17T10:30:21Z urn:sha1:2a884c612b10b27f4be2cc6dd689bfe448d9361a Previously, we had a start and a done of the calculation printed by higher-level code, but this got intermixed by progress reporting from an external solver or the output of autoremove code… The higherlevel code is now only responsible for instantiating a progress object of its choosing (if it wants progress after all) and the rest will be handled by the upgrade code. Either it is used to show the progress of the external solver or the internal solver will give some hints about its overall progress. The later isn't really a proper progress as it will jump forward after each substep, but that is at least a bit better than before without any progress indication. Fixes also the 'strange' non-display of this progress line in -q=1, while all others are shown, which is reflected by all testcase changes. 2012-06-12T13:40:56Z David Kalnischkies kalnischkies@gmail.com 2012-06-12T13:40:56Z urn:sha1:82c6f7528d583431722ef180b6064b86b644ad85