/usr/lib/ghc-doc/hoogle/libghc-diagrams-cairo-doc.txt is in libghc-diagrams-cairo-doc 1.4-2build4.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-diagrams-cairo-doc/html/diagrams-cairo.txt