cache-storage-mode

Specify the mechanism used by the Dune cache for storage.

(cache-storage-mode <setting>)

where <setting> is one of:

auto lets Dune decide the best mechanism to use.
hardlink uses hard links for entries in the cache. If the cache is stored in a different partition than the one where the build is taking place, then this mode will not work and copy should be used instead.
copy copies entries to the cache. This is less efficient than using hard links.