$ singularity pull oras://ghcr.io/openfreeenergy/openfe:1.6.1-apptainer
INFO[0000] trying next host - response was http.StatusNotFound host=ghcr.io
FATAL: While pulling image from oci registry: error fetching image to cache: failed to get checksum for oras://ghcr.io/openfreeenergy/openfe:1.6.1-apptainer: while resolving reference: ghcr.io/openfreeenergy/openfe:1.6.1-apptainer: not found
Works fine with the 1.6.0 image.