/usr/lib/ghc-doc/hoogle/html.txt is in libghc-html-doc 1.0.1.2-7.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-html-doc/html/html.txt
/usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-html-doc/html/html.txt