/usr/lib/ghc-doc/hoogle/libghc-xmlhtml-doc.txt is in libghc-xmlhtml-doc 0.2.3.4-5build1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-xmlhtml-doc/html/xmlhtml.txt