/usr/lib/ghc-doc/hoogle/darcs.txt is in libghc-darcs-doc 2.8.4-3build1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-darcs-doc/html/darcs.txt
/usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-darcs-doc/html/darcs.txt