/usr/lib/ghc-doc/hoogle/hxt.txt is in libghc-hxt-doc 9.3.1.1-2build1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-hxt-doc/html/hxt.txt
/usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-hxt-doc/html/hxt.txt