I wanted to know which version of RHEL used to build RHCOS 4.6.8? It would help me understand the platform and debug few issues.
Somewhere in the customer portal there should be a KS that provides that information, but if you have cluster-admin access to a cluster you can try:
$ oc debug node/name-of-the-node ... # chroot /host ... # cat /etc/system-release ... RHEL_VERSION="8.2" ...
That was from OpenShift 4.5.4 in a DO280-v4.5 classroom.
CoreOS is built from RHEL rpms. You can even use the rpm command from an oc debug shell to see the exact package releases that are installed in a node.
Of course it is not just RHEL 8.2, it is 8.2 with all z-stream updates at the time the CoreOS image was built for that OpenShift release.