/usr/lib/ghc-doc/hoogle/libghc-trifecta-doc.txt is in libghc-trifecta-doc 1.6.2.1-1build8.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-trifecta-doc/html/trifecta.txt