bug(26.10): `chisel cut` failing for 26.10

[lczyk]

chisel cut against ubuntu 26.10 fails for every package on every arch with:

$ chisel cut --root rootfs --release ubunutu-26.10 --ignore=unstable libc6_libs
2026/07/06 22:08:18 Consulting release repository...
2026/07/06 22:08:19 Fetching current ubuntu-26.10 release...
2026/07/06 22:08:19 Processing ubuntu-26.10 release...
2026/07/06 22:08:29 Warning: This release is in the "unstable" maintenance status. See https://documentation.ubuntu.com/chisel/en/latest/reference/chisel-releases/chisel.yaml/#maintenance to be safe
2026/07/06 22:08:29 Selecting slices...
2026/07/06 22:08:29 Fetching ubuntu 26.10 stonking suite details...
2026/07/06 22:08:29 Release date: Mon, 06 Jul 2026 19:14:03 UTC
error: main/binary-arm64/Packages is missing from stonking main component digests

chisel only reads sha256 from InRelease. Stonking archives have only sha256 (at least so far).

$ curl -sSL http://ports.ubuntu.com/ubuntu-ports/dists/stonking/InRelease | grep -E '^(MD5Sum|SHA1|SHA256|SHA512):'
SHA512:

$ curl -sSL http://archive.ubuntu.com/ubuntu/dists/resolute/InRelease | grep -E '^(MD5Sum|SHA1|SHA256|SHA512):'
MD5Sum:
SHA1:
SHA256:

fix proposal

use strongest present acceptable checksum

[utkarsh2102]

Hi,

Stonking archives have only sha256 (at least so far).

FWIW, this is by design. Launchpad enabled a new publisher configuration for stonking which reduced the list of published hashes in the archive index files to sha512 (dropping md5sum, sha1 and sha256).