pub fn host_machine_id() -> Option<String>Expand description
A durable per-machine identifier that survives reboots.
/etc/machine-id is the systemd-era answer and /var/lib/dbus/machine-id
the older one; a host with neither falls back to a boot-scoped id, which is
weaker but still never shared between machines.
Deliberately not [crate::platform::host::machine_id_from], which treats
an unreadable machine-id file as a hard error. That strictness exists to
stop one user’s processes deriving two different identities and each
believing it is the singleton. A fact reported to a caller that is only
comparing machines has the opposite preference: keep looking, and answer
with the best id available.