/usr/lib/ghc-doc/hoogle/citeproc-hs.txt is in libghc-citeproc-hs-doc 0.3.9-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-citeproc-hs-doc/html/citeproc-hs.txt