/usr/lib/ghc-doc/hoogle/hostname.txt is in libghc-hostname-doc 1.0-6.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-hostname-doc/html/hostname.txt
/usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-hostname-doc/html/hostname.txt