This is unnecessary when cross-building from Linux/macOS.
Additionally, cp -p appears to be broken on macOS Big Sur
(https://openradar.appspot.com/8957219).
For some unknown reason this commit appears to fix
the freezes when building failures on macOS Big Sur.
This also fixes building in docker with volume mounts
with ACLs, since setting the ACL with cp -p fails otherwise.
Tested By: gnn (macOS Big Sur), Nathaniel Wesley Filardo (docker)