apt/test/integration/test-bug-632221-cross-dependency-satisfaction, branch main

solver3: Rename decision to assignment

2026-01-05T21:20:24Z

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.

solver3: Verbose error messages

2025-03-08T22:18:05Z

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.

solver3: Only enqueue shared dependencies at the package level

2025-02-14T18:08:45Z

Dependencies shared by all versions are enqueued at the package level, so avoid enqueuing duplicates at the version level. This presumably has no meaningful impact on performance, potentially a negative performance impact on some workloads as we now need to find the duplicates again; it can become useful when there is a lot of backtracking. More importantly though this improves error messages, because now we can say that "all versions of foo depend on X", rather than saying "foo=1 depends on X" and you are left wondering why we did not select "foo=2". In this commit though, improved error messages are not implemented, they depend on redesigning the reason tracking to use clauses. Also the rationale tracking includes a lot more dependencies of the form "pkg:arch=version -> pkg:arch" which are annoying. Improved error messages should fold them into one node.

test: Support the 3.0 solver in most existing test cases

2024-05-24T15:01:35Z

Highlights: - test-bug-618848-always-respect-user-requests: (Do not) Support 3.0 solver A manually installed package is never removed just because we request the removal of its dependency in solver3. - test-bug-657695-resolver-breaks-on-virtuals: Support 3.0 solver For manually installed packages, solver 3.0 would require some new xserver-xorg-video-driver to Conflict+Replace+Provides the old one (once the logic is implemented), but that does seem reasonable. - test-bug-720597-build-dep-purge: Support 3.0 solver This needs a simple aptmark auto because pkga is removed by the build-dep. But further adjustments are necessary because it weirdly tested for no autoremovable packages before installing pkgc. - test-bug-960705-*: Support 3.0 solver Bit awkward to deal with; notably the protect to conflict doesn't actually work anymore and that is a feature these days.

Do not strip M-A for native build-dep resolution

2021-09-04T13:35:15Z

Back than M-A was added to build-dependencies (#558104) only the qualifiers :native and :any were considered at first which for the native case behave the same, so stripping was a good idea. Nowadays we could encounter arch-qualified dependencies, too, through – or slightly more likely conflicts perhaps – at least in theory as in practice native build-dep operations in Debian and elsewhere wouldn't have other architectures available anyhow. Still, we have full support for all this for the crossbuilding case which makes active use of this (at least is far more likely to do so), so it seems better to converge on one edgecase rather than keeping two in active use and so produce potentially different results for not specifying -a and -a $native.

Keep status number if candidate is discarded for kept back display

2020-05-23T15:59:19Z

It looks like hack and therefore I wanted this to be a very isolated commit so we can find it & revert it easily if need be, but for now it seems to work. The idea is that Status is telling us how the candidate is in relation to the current installed version which is used to figure out if a package is "kept back" by the algorithm or not, but by discarding the candidate version we loose this information. Ideally we would keep better tabs on what we do to a package and why, but for now that seems okayish. It will cause the wrong version to be displayed though as if the package is installed the installed version becomes the candidate and hence (installed => installed) is displayed.

Reset candidate version explicitly for internal state-keeping

2020-05-23T15:58:42Z

For a (partially) installed package like the one MarkInstall operates on at the moment we want to discard the candidate from, we have to first remove the package from the internal state keeping to have proper broken counts and such and only then reset the candidate version which is a trivial operation in comparison. Take a look at the testcase: Now, what is the problem? Correct, git:i386. Didn't see that coming, right? It is M-A:foreign so apt tries to switch the architecture of git here (which is pointless, it knows that this won't work, but lets fix that in another commit) will eventually realize that it can't install it and wants to discard the candidate of git:i386 first removing the broken indication like it should, removing the install flag and then reapplies the broken indication: Expect it doesn't as it wants to do that over the candidate version which the package no longer had so seemingly nothing is broken. It is a bit of a hairball to figure out which commit it is exactly that is wrong here as they are all influencing each other a bit, but >= 2.1 is an acceptable ballpark. Bisect says 57df273 but that is mostly a lie. Closes: #961266

Read dpkg tables to handle architecture wildcards

2017-01-17T00:43:50Z

Our implementation of wildcards was rudimentary. It worked for some common ones, but it was also broken: For example, armel matched any-armel, but should match any-arm. With this commit, we load the correct tables from dpkg. Supported are both triplets and quadruplet tables (the latter introduced in dpkg 1.18.11). There are some odd things we have to deal with in the cache filter for historical and API reasons: * The character "*" must be accepted as an alternative to any - in fact it may appear anywhere in the wildcard as we also allow fnmatch() style wildcard matching on the commandline. * The code might get passed an arch with a minus at the end, for example the cmdline "install apt:any-arm-" will first try to check if any-arm- is a valid architecture. We deal with this by rejecting any wildcard ending in a minus. * Triplets are actually implemented by extending them to faux quadruplets - by prepending a "base" component for the architecture tuple, and "any" if there is a wildcard component. Once we have constructed a wildcard, it is transformed into an fnmatch() expression for historical reasons. In the future, we should really get a tuple class and implement matching in a better, more explicit way. This does for now though - it passes all the test cases and accepts all things it should accept. Closes: #748936 Thanks: James Clarke for the initial patch

reimplement build-dep via apts normal resolver

2016-01-25T17:15:44Z

build-dep was implemented by parsing the build-dependencies of a package and figuring out which packages to install/remove based on this. That means that for the first level of dependencies build-dep was implementing its very own resolver with all the benefits (aka: bugs) this gives us for not using the existing resolver for all levels. Making this work involves generating a dummy binary package with fitting Depends and Conflicts and as we can't create them out of thin air the cache generation needs to be involved so we end up writing a Packages file which we want to parse – after we have parsed the other Packages files already. With .dsc/.deb files we could add them before we started parsing anything. With a bit of care we can avoid generating too much data we have to throw away again (as many parts assume that e.g. the count of packages doesn't change midair), so that on a speed front there shouldn't be much of a difference, but output can be slightly confusing as if we have a completely valid cache on disk the "Reading package lists... Done" is printed two times – but apt is pretty quick about it in that case. Closes: #137560, #444930, #489911, #583914, #728317, #812173

tests: support spaces in path and TMPDIR

2015-12-19T22:04:34Z

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