/usr/lib/ghc-doc/hoogle/wai-websockets.txt is in libghc-wai-websockets-doc 1.3.2.1-1build1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-wai-websockets-doc/html/wai-websockets.txt