Lambda container and oci image manifest type

Hello,

I am trying to use podman to build lambda container.

When manifest type is application/vnd.oci.image.manifest.v1+json I get the following error:

"The image manifest or layer media type for the source image <snip> is not supported."

When I set manifest type to application/vnd.docker.distribution.manifest.v2+json it works.

In lambda faq (https://aws.amazon.com/lambda/faqs/) I read:

""" You can use any container tooling as long as it supports one of the following container image manifest formats: Docker Image Manifest V2 Schema 2 (used with Docker version 1.10 and newer) or Open Container Initiative (OCI) Specifications (v1.0 and up). For example, you can use native container tools (i.e. docker run, docker compose, Buildah and Packer) to define your functions as a container image and deploy to Lambda. """

So it should be supported.

I do not see what is wrong as all seems right.

Diff of inspect if I remove GraphDriver and expected timestamp and hash modifications... ends up with:

-        "ManifestType": "application/vnd.docker.distribution.manifest.v2+json",
+        "ManifestType": "application/vnd.oci.image.manifest.v1+json",

Does anyone have a clue?

Reproduce with this simple Containerfile:

from public.ecr.aws/lambda/python:3.9

run touch a

# works:
podman --format docker build .
# Does not work:
podman --format oci build .