ERROR exporting to oci image format during docker buildx build

[MarkCarbonell98]

While running the command:

docker buildx build --platform linux/arm/v7,linux/amd64 . -f _docker/base.raspberry.Dockerfile  --load

With the following Dockerfile:

FROM arm32v7/docker:19.03.8

RUN apk add openssh \
            ca-certificates

RUN apk update \
    && apk add py-pip \
            python-dev \
            libffi-dev \
            openssl-dev \
            gcc \
            libc-dev \
            make

RUN pip install docker-compose

RUN pip install awscli

RUN apk add bash \
            vim \
            git \
            jq \
            sed \
            curl \
            gzip \
            bind-tools

CMD ["/bin/bash"]

I get the error: ERROR exporting to oci image format

Apparently the docker exporter does not support exporting manifests lists. That's odd. Wasn't this issue fixed in a previous release ?

Notice: This does not happen when running it without the --platform flag. But that's useless in my case because it must be build for both linux/amd64 and linux/armv7 architectures.

Has anyone seen this issue before ? Or has an idea on how to fix it ?

Docker version: 19.03.8, build afacb8b
Linux Kernel version: 4.19.97-v7l+
OS:

PRETTY_NAME="Raspbian GNU/Linux 10 (buster)"
NAME="Raspbian GNU/Linux"
VERSION_ID="10"
VERSION="10 (buster)"
VERSION_CODENAME=buster
ID=raspbian
ID_LIKE=debian
HOME_URL="http://www.raspbian.org/"
SUPPORT_URL="http://www.raspbian.org/RaspbianForums"
BUG_REPORT_URL="http://www.raspbian.org/RaspbianBugs"

[tonistiigi]

docker load does not currently support loading manifest lists and images in docker images can only be for a single platform. This is documented in https://github.com/docker/buildx#docker