#1000390 aspcud fails to resolve upgrade problem, apt succeeds

Package:
aspcud,apt
Source:
apt aspcud
Submitter:
Julian Andres Klode
Date:
2026-02-16 22:25:02 UTC
Severity:
important
#1000390#5
Date:
2021-11-22 12:28:43 UTC
From:
To:
The attached problem is UNSAT according to aspcud, but apt finds a
solution.

For comparison:

- Z3 prototype solver manages to upgrade 135 packages (not the gcc ones)
- APT's internal solver manages to upgrade 177 packages

I actually did the upgrade, and APT was correct.
#1000390#10
Date:
2021-11-30 11:31:25 UTC
From:
To:
Attached is another instance with very similar results (slightly
different numbers).
#1000390#15
Date:
2026-02-16 22:24:07 UTC
From:
To:
Control: reassign -1 aspcud, apt-cudf
(fixing this assignment too, it might be in the cudf translation)

Attached is another instance. Booted a docker container debian:testing,
installed `pandoc aspcud apt-cudf` and tried to dist-upgrade.

Comparison of results:

apt dist-upgrade:
    Keeps back pandoc-data
apt dist-upgrade --solver internal (old solver):
    Removes pandoc
aptitude dist-upgrade:
    Prompts, suggests to keep back pandoc-data
apt dist-upgrade --solver aspcud:
    W: Encountered an unexpected section with 1 fields: Message: (UNSAT) No Solutions according to the given preferences

Upgrades are fundamentally broken.,