/usr/lib/ghc-doc/hoogle/libxml-sax.txt is in libghc-libxml-sax-doc 0.7.3-2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-libxml-sax-doc/html/libxml-sax.txt