`oc adm catalog mirror` doesn't work for air-gapped clusters in Red Hat OpenShift Container Platform 4.x

Issue

oc adm catalog mirror doesn't work for air-gapped clusters in Red Hat OpenShift Container Platform 4.x

oc adm catalog mirror doesn't work for air-gapped clusters. This fails on step:

$ oc adm catalog mirror \
    file://local/index/<repo>/<index_image>:<tag> \
    <mirror_registry>:<port>/<namespace> \
    [-a ${REG_CREDS}] \
    [--insecure]

With messages like:

Failed to mirror image to the remote registry from the local.
error: unable to retrieve source image file://local/index/olmqe/redhat-operator-index/openshift4/ose-logging-fluentd manifest sha256:11ccb42f3d96b065f7d94879611a7aefabbe509b522c11ac36be7a1c959a34d6: open v2/local/index/olmqe/redhat-operator-index/openshift4/ose-logging-fluentd/manifests/sha256:11ccb42f3d96b065f7d94879611a7aefabbe509b522c11ac36be7a1c959a34d6: no such file or directory