[systemd-devel] snapshots not isolatable?

[Sun Bing]

hi all,

i wanna try out the systemd.snapshots for my suspend/hibernation
configuration. but it seems the snapshots are not isolatable.

"systemdctl isolate foo.snapshot" just throws an error "Failed to issue
method call: Operation refused, unit may not be isolated."

and the outputs of "systemctl show foo.snapshot":
...
CanIsolate=no
...
AllowIsolate=no
...

according to "man systemd.snapshot":
...Later on, the user may choose to return to the saved state via
systemctl isolate....

what am i missing?

btw, the version in my host is 198.

best.