davide authored Jul 03, 2019 and Marge Bot committed Jul 08, 2019

This is important as in hard link mode shake  makes all such files
read only to avoid accidentally modifying cache files via the
hard link. It turns out, many Hadrian rules attempt read access
to such files and hence fail in the hard link mode. These
rules could be refactored to avoid write access, but using
copy instead of hard link a much simpler solution.