Auth failures for quay.io

I’d appreciate a little direction, please. A documentation link would be awesome but so would a solution.

Running on Kubernetes…

Within the Dockerfile for the Publish Image step of a pipeline, like so:
- name: Publish Image
steps:
- publishImageConfig:
dockerfilePath: ./images/Dockerfile
buildContext: .
tag: rancher-1
pushRemote: true
registry: quay.io/foo/reporting
imagePullSecret: quay-pull-secret
env:
JRE_TAG: 8u181
LEIN_TAG: 2.8
REGISTRY: quay.io/foo

in the Dockerfile, I’m trying to pull an image in FROM from the quay registry, but with auth failure
so no luck

FROM ${REGISTRY}/leiningen:${LEIN_TAG} AS lein