/usr/lib/ghc-doc/hoogle/basic-prelude.txt is in libghc-basic-prelude-doc 0.3.8-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-basic-prelude-doc/html/basic-prelude.txt