/usr/lib/ghc-doc/hoogle/xhtml.txt is in libghc-xhtml-doc 3000.2.1-4.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-xhtml-doc/html/xhtml.txt
/usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-xhtml-doc/html/xhtml.txt