If a new pseudo-essential package was added to testing *and* it is
mutually-exclusive with an existing member, britney would incorrectly
flag it as uninstallable (unless another change triggered a cache
invalidation of the pseudo-essential set).
With this commit, the cache invalidation is now done based on whether
we add something that *might* be in the (effective) pseudo-essential
set. It is an overapproximation as there are cases where the
invalidation is unnecessary, but at the moment it is not a performance
concern.
Closes: https://bugs.debian.org/944190
Signed-off-by: Niels Thykier <niels@thykier.net>
The InstallabilityTester is suffering from a lack of clear purpose
because it serves multiple. This commit extracts most of one of these
purposes into the BinaryPackageUniverse class while retaining the
original API of the InstallabilityTester.
Signed-off-by: Niels Thykier <niels@thykier.net>
Britney has a special case for essential packages to ensure that any
package that with essential packages are not installable. This check
did not account for a case, where a package is not co-installable with
two or more pseudo-essential package part of the same OR dependency.
A contrived example based on real world data:
Package: foo
# Conflict with all providers of "awk"
Conflicts: mawk | gawk | original-awk
This alone is actually not sufficient to trigger the bug, as
_get_min_pseudo_ess_set is in theory some times smart enough to pick
an "obvious" solution between the pseudo-essential option.
When it does, one of the above ends up in the (de-facto) essential set
and then the installability tester correctly rejects "foo".
Though, even with the fix above, the handling for this is probably not
correct if the essential set is not (fully co-)installable. However,
that basically only happens if we are bootstrapping an architecture
(or testing is royally broken, in which case this is the least of our
worries).
Signed-off-by: Niels Thykier <niels@thykier.net>
Add some "no cover" to some unrecoverable exceptions
(e.g. misconfiguration) or base-class methods that are not intended to
be invoked.
Signed-off-by: Niels Thykier <niels@thykier.net>
Iain Lane
Ivo De Decker
Niels Thykier
Paul Gevers