/usr/lib/ghc-doc/hoogle/download-curl.txt is in libghc-download-curl-doc 0.1.4-3build1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-download-curl-doc/html/download-curl.txt