A clone group is only visible while both copies are on disk, and the
run then deletes the clone, so writing only what this run saw erased
every mapping an earlier run had recorded. One real run took the map
from 69 entries to 1, and the canonical zips silently stopped answering
to the names they stand in for.
The map is merged now, the 68 lost entries are restored, and the one
whose canonical file is no longer in the collection is dropped.
Abdessamad Derraz
4ecb65b8d9