/usr/lib/ghc-doc/hoogle/bifunctors.txt is in libghc-bifunctors-doc 4.1.1.1-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-bifunctors-doc/html/bifunctors.txt