/usr/lib/ghc-doc/hoogle/bytestring-nums.txt is in libghc-bytestring-nums-doc 0.3.5-5.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-bytestring-nums-doc/html/bytestring-nums.txt