apt/test, branch 3.1.15Debians commandline package managerhttps://git.kalnischkies.de/apt/atom?h=3.1.152026-01-31T16:30:20Zsolver3: Use classical watchers for propagation2026-01-31T16:30:20ZJulian Andres Klodejak@debian.org2025-12-29T17:47:15Zurn: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
variants: Do not report unsupported variants in repositories2026-01-23T11:04:31ZJulian Andres Klodejak@debian.org2026-01-23T11:03:04Zurn:sha1:49e80c2d9061372e0ec697be43bcba4c451b7752
We configure all variants the CPU supports as active, but repositories
usually do not provide all of them, so let's not be noisy.
why: Render info about all providers on virtual packages2026-01-20T13:07:15ZJulian Andres Klodejak@debian.org2026-01-20T13:04:20Zurn:sha1:34876ed2e5cdf504e2a4f9721486d279ae5f3be6
Refactor code into a doOne helper lambda, and then add loop
over the providers to use it.
This fixes a crash seen by Benjamin in a nice way than just
failing :)
Reported-by: Benjamin Drung
solver3: Rename decision to assignment2026-01-05T21:20:24ZJulian Andres Klodejak@debian.org2025-12-28T15:56:28Zurn: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.
Correctly copy provided version in m-a lazy-init2025-11-10T10:01:02ZJulian Andres Klodejak@debian.org2025-11-10T09:41:20Zurn:sha1:2f4299bf39c85b694876cb8030fae0887e8b5edc
When a provides was copied, we inadvertently copied the package
version instead of the provided version. Copy the provided version
instead.
Closes: #1120463
Revert "depcache: Allow changing multi-arch versions for removed siblings"2025-10-26T08:31:20ZJulian Andres Klodejak@debian.org2025-10-26T08:14:20Zurn:sha1:22786e32b613518ae3a5cd07e9e2f1419b2c6552
This reverts commit 74636b64a7ee56637a3ce4ddc1d060ca9f8b77e1.
Adjust the test case accordingly, as it is no longer possible to
install libgcc-s1:s390x. We need to sort this out in the ToDepCache
translation layer at a later time.
Sadly the depcache rejects valid solutions like this; solving this
isn't trivial. Technically we need to split up the FromUser and
auto-bit handling to solve this, but even then, MarkDelete() with
FromUser=0 moves the auto-bit on metapackages; this doesn't happen
when doing FromUser=1, so we can't always do FromUser=1.
Fixes: a3fca052ca21ad222ac7f2fdd7f3fe84b44beb60
test: Correctly skip tests when not using -j2025-10-26T07:28:35ZJulian Andres Klodejak@debian.org2025-10-26T06:59:52Zurn:sha1:487ce0983c2008991566b4cfb269fd7d29a08e98
We never implemented comment support in the skip test file for
-j as we only run with -j, but the debian/tests/run-tests runs
without parallelism.
tests: Do not skip tests for --solver internal2025-10-26T07:28:35ZJulian Andres Klodejak@debian.org2025-10-26T06:58:43Zurn:sha1:78da58ec0c1cdbda6cdd22c63f85ddac703bb0d6
Remove the exports for the default as we don't want those
inherited, they can just be reset. Set the skip file to
/dev/null when a solver is selected, to make sure that
tests don't fall back to the default skip file.
Adjust test cases to treat 3.0 as default APT_SOLVER if not set2025-10-26T07:28:08ZJulian Andres Klodejak@debian.org2025-10-26T07:24:39Zurn:sha1:5e8e69cdd6b512480f3208298725e1e44c80f06e
Not needed so far because we export a default 3.0 APT_SOLVER, but
quite useful if we stop doing so (next commit).
solver3: Allow removing manually installed packages2025-10-25T20:16:54ZJulian Andres Klodejak@debian.org2025-10-25T19:31:34Zurn:sha1:a3fca052ca21ad222ac7f2fdd7f3fe84b44beb60