/usr/lib/ghc-doc/hoogle/yesod-routes.txt is in libghc-yesod-routes-doc 1.2.0.1-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-yesod-routes-doc/html/yesod-routes.txt