/usr/lib/ghc-doc/hoogle/libghc-filemanip-doc.txt is in libghc-filemanip-doc 0.3.6.3-4.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-filemanip-doc/html/filemanip.txt