File "pr10693_bad.ml", line 27, characters 26-27:
27 | module Bad (A : S') : S = A
                               ^
Error: Signature mismatch:
       Modules do not match:
         sig val x : 'a option module M : Dep -> S end
       is not included in
         S
       In module "M":
       Modules do not match:
         Dep -> S
       is not included in
         functor (X : Dep) ->
           sig
             val x : X.t option
             module M : functor (Y : Dep) -> sig val x : X.t option end
           end
       In module "M":
       Modules do not match:
         S
       is not included in
         sig
           val x : X.t option
           module M : functor (Y : Dep) -> sig val x : X.t option end
         end
       In module "M.M":
       Modules do not match:
         functor (X : Dep) ->
           sig
             val x : X.t option
             module M : functor (Y : Dep) -> sig val x : X.t option end
           end
       is not included in
         functor (Y : Dep) -> sig val x : X.t option end
       In module "M.M":
       Modules do not match:
         sig
           val x : X.t option
           module M : functor (Y : Dep) -> sig val x : X.t option end
         end
       is not included in
         sig val x : X.t option end
       In module "M.M":
       Values do not match:
         val x : X.t option
       is not included in
         val x : X/2.t option
       The type "X.t option" is not compatible with the type "X/2.t option"
       Type "X.t" is not compatible with type "X/2.t"
       File "_none_", line 1:
         Definition of module "X"
       File "_none_", line 1:
         Definition of module "X/2"
       File "pr10693_bad.ml", line 17, characters 6-24: Expected declaration
       File "pr10693_bad.ml", line 15, characters 4-22: Actual declaration