commit b3014c1c69 changed
GetRootlessRuntimeDir() to return an empty string for root, so that
its value is not exported as XDG_RUNTIME_DIR, and other programs like
crun can use a better default.
Now GetRootlessPauseProcessPidPath() uses homedir.GetRuntimeDir().
The homedir.GetRuntimeDir() function returns a value also when running
as root so it can be used inside a nested Podman.
Closes: https://github.com/containers/podman/issues/22327
Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>