Is there a way to get the docker registry name from an env var? I have a docker image like:

docker_image(
    name="my_app",
    source="./app/Dockerfile",
    dependencies=["my_app:app"],
    restartable=True,
    registries=["{build_args.DOCKER_REGISTRY}"],
    repository="{build_args.DOCKER_REPO}",
    image_tags=["{build_args.VERSION}", "latest"],
    extra_build_args=["version=${build_args.VERSION}"]
)

The repo seems to work, but the registry interpolation doesn't seem to. I get the following error:

Process 'Building docker image {build_args.DOCKER_REPO}/my_app/app:0.1.0-509546a +1 additional tag.' failed with exit code 125