/usr/lib/ghc-doc/hoogle/libghc-yesod-auth-oauth-doc.txt is in libghc-yesod-auth-oauth-doc 1.4.0.2-3build1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-yesod-auth-oauth-doc/html/yesod-auth-oauth.txt