/usr/lib/ghc-doc/hoogle/keys.txt is in libghc-keys-doc 3.10-1build3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-keys-doc/html/keys.txt
/usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-keys-doc/html/keys.txt