/usr/lib/ghc-doc/hoogle/libghc-yesod-auth-oauth2-doc.txt is in libghc-yesod-auth-oauth2-doc 0.3.0-1build3.
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-oauth2-doc/html/yesod-auth-oauth2.txt