Bizarre new flake:

[It] podman checkpoint latest running container
...
# podman-remote [options] container checkpoint second
Error: checkpoint/restore requires at least CRIU 31100

All other checkpoint/restore tests pass on that same task, so obviously this is a false error.

Only one instance in my logs: f37 remote

First step, I would suggest, might be to instrument libpod/container_internal_common.go:checkpointRestoreSupported() so it emits the criu version it thinks it's finding.