checkpoint-state
An advisory: it explains, and blocks nothing, on a command reaching for a tree's identity, which a revision alone cannot give.
What it catches
A command reaching for a tree's identity, which a revision alone cannot give.
Seeing it
A verdict names its rule in brackets, which is how you got here:
advise [checkpoint-state]: ...
magus describe rule checkpoint-state prints the same entry at a terminal, and
magus describe rules lists every rule this workspace enforces.