up xpkg build breaks on Docker 25.0

[nekr0z]

What happened?

On Docker 25.0, attempting to up xpkg build --controller $something results in

up: error: xpkg.buildCmd.Run(): unable to calculate manifest: blob sha256:whatever not found

Downgrading Docker to 24.0.7 restores normal behavior.

moby/moby#44598 may be related, though I'm not sure.

[nekr0z]

Tentatively linking to google/go-containerregistry#1870

[bobh66]

@tnthornton - is there a reason that docker/docker is pinned back to v20.10? It is incompatible with v25+

[tnthornton]

@bobh66 it looks like we needed to pin it due to a transitive dependency from helm helm/helm#11821. There's been some movement in that issue since, so maybe we can make some progress in removing that specific pin.