/usr/lib/ghc-doc/hoogle/entropy.txt is in libghc-entropy-doc 0.2.1-5.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-entropy-doc/html/entropy.txt
/usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-entropy-doc/html/entropy.txt