/usr/lib/ghc-doc/hoogle/yaml.txt is in libghc-yaml-doc 0.8.5.1-2build2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-yaml-doc/html/yaml.txt
/usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-yaml-doc/html/yaml.txt