docker manifest create refuses a source that is itself a manifest list:
ERROR: ...:<tag>-amd64 is a manifest list
With Docker containerd image store, docker build --platform linux/amd64
produces an OCI index rather than a plain manifest, so BOTH per-arch tags are
lists and the combine fails — after the slow multi-hundred-MB pushes have
already succeeded. The failure mode is nasty: the per-arch tags are published
and the PLAIN tag, the one both Deployments reference, is absent. Hit on
12.11.1-ci6, 2026-08-31.
buildx imagetools create accepts indexes as sources and combines registry-side,
so it works with either image store. Verification switches to imagetools
inspect and now asserts both linux/amd64 and linux/arm64 specifically, rather
than counting two distinct architecture strings.
agent