Can't concurrently build boot images for multiple architectures

[vraiti]

It appears that bootc gets confused if you try to build the same image for two architectures concurrently using the --target-arch option.

I have the following script to produce a multi-arch manifest of disk image artifacts from bootc image builder:

WDIR=/home/vraiti/scrap
URL=quay.io/flightctl/flightctl-agent-rhel
DST_URL=quay.io/vraiti/artifacts:parallel
cd $WDIR
buildah manifest create bootc-images

for ARCH in amd64 arm64; do
for FORMAT in qcow2 raw; do

  echo "$WDIR/run-bib.sh $ARCH $FORMAT $URL:bootstrap > $ARCH-$FORMAT.log" >> args

done
done

cat args | xargs -I CMD --max-procs=4 bash -c CMD
buildah manifest push --all bootc-images docker://$DST_URL

This is the run-bib.sh script:

#!/usr/bin/env bash

ARCH=$1
FORMAT=$2
URL=$3

OUTPUT="$ARCH-$FORMAT"
mkdir $OUTPUT

sudo podman run --rm \
  -it \
  --privileged \
  --pull=newer \
  --security-opt label=type:unconfined_t \
  -v $(pwd)/$OUTPUT:/output \
  -v /var/lib/containers/storage:/var/lib/containers/storage \
  quay.io/centos-bootc/bootc-image-builder:latest \
  --type $FORMAT \
  --target-arch $ARCH \
    "$URL"    

if [ -f $OUTPUT/image/disk.raw ]; then
  OUTPUT=$OUTPUT/image/disk.raw
else
  OUTPUT=$OUTPUT/qcow2/disk.qcow2
fi

buildah manifest add bootc-images \
  --artifact $OUTPUT \
  --artifact-type application/vnd.diskimage+$FORMAT \
  --os $FORMAT \
  --arch $ARCH

Running this script will either produce

error: cannot build manifest: image found is for unexpected architecture "aarch64" (expected "x86_64"), if that is intentional, please make sure --target-arch matches

or

error: cannot build manifest: image found is for unexpected architecture "x86_64" (expected "aarch64"), if that is intentional, please make sure --target-arch matches

And the corresponding architecture fails to build.

If I remove -v /var/lib/containers/storage:/var/lib/containers/storage \, then the script works fine.