/usr/lib/ghc-doc/hoogle/xml.txt is in libghc-xml-doc 1.3.12-3build1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-xml-doc/html/xml.txt
/usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-xml-doc/html/xml.txt