The new Installability Tester (IT) module replaces the remaining
C-parts. Unlike C-implementation, it does not give up and emit an
"AIEEE" half-way through.
In order to determine installability, it uses two sets "musts" and
"never". As the names suggest, the sets represents the packages that
must be (co-)installable with the package being tested and those that
can never be co-installable. For a package to be installable, "musts"
and "never" have remain disjoint.
These sets are also used to reduce the number of alternatives that are
available to satisfy a given dependency. When these sets are unable
to remove the choice completely, the new IT defers the choice to later.
This occasionally reduces backtracking as a later package may conflict
or unconditionally depend on one of the remaining alternatives.
Signed-off-by: Niels Thykier <niels@thykier.net>
We stopped populating the element with real data some time ago, it's
time to drop it entirely.
Signed-off-by: Adam D. Barratt <adam@adam-barratt.org.uk>
Multiarch adds a Depends: foo:any syntax, permitted only if the
target of the dependency is "Multi-Arch: allowed". This has
been supported by dpkg and apt for some time and is now safe to
use in unstable.
[Adam D. Barratt: adjusted to use consts.py]
Signed-off-by: Adam D. Barratt <adam@adam-barratt.org.uk>
