This was removed in 5ac5067 because it was implemented poorly.

A new implementation must satisfy the following requirements:

• Friendly to shell globbing (e.g. aquarium pointer -y files/* /tmp should work, as before).
• Works recursively, so no simple fcopyfile (should prolly do as in Bob the Builder for this, in fine it'd be nice to have a common header-only library for these kinds of stupid FS functions).
• Is safe; you shouldn't be able to copy over files you don't have access to so you can read them.
• Respects permissions, but I have approx 0 clue how to go about this. Do I set all UID's and GID's to 0?

(Personal note: once this is all done, I can work on the new images for Ananas!)