/usr/lib/ghc-doc/hoogle/libghc-multiset-comb-doc.txt is in libghc-multiset-comb-doc 0.2.4.1-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-multiset-comb-doc/html/multiset-comb.txt