/usr/lib/ghc-doc/hoogle/magic.txt is in libghc-magic-doc 1.0.8-12.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-magic-doc/html/magic.txt
/usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-magic-doc/html/magic.txt