/usr/lib/ghc-doc/hoogle/vault.txt is in libghc-vault-doc 0.3.0.2-1build1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-vault-doc/html/vault.txt
/usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-vault-doc/html/vault.txt