/usr/lib/ghc-doc/hoogle/wai-app-file-cgi.txt is in libghc-wai-app-file-cgi-doc 0.8.3-2build8.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-wai-app-file-cgi-doc/html/wai-app-file-cgi.txt