/usr/lib/ghc-doc/hoogle/libghc-parallel-tree-search-doc.txt is in libghc-parallel-tree-search-doc 0.4.1-1build1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-parallel-tree-search-doc/html/parallel-tree-search.txt