Merge remote-tracking branch 'upstream/main' into as-parameter

ocaml/typing/typemod.ml

@@ -86,6 +86,7 @@ type error =
   | Unpackable_local_modtype_subst of Path.t
   | With_cannot_remove_packed_modtype of Path.t * module_type
   | Toplevel_nonvalue of string * sort
+  | Strengthening_mismatch of Longident.t * Includemod.explanation
   | Cannot_implement_parameter of filepath
   | Cannot_pack_parameter
   | Cannot_compile_implementation_as_parameter
@@ -3691,6 +3692,14 @@ let report_error ~loc _env = function
       Location.errorf ~loc
         "@[Top-level module bindings must have layout value, but@ \
          %s has layout@ %a.@]" id Sort.format sort
+ | Strengthening_mismatch(lid, explanation) ->
+      let main = Includemod_errorprinter.err_msgs explanation in
+      Location.errorf ~loc
+        "@[<v>\
+           @[In this strengthened module type, the type of %a@ \
+             does not match the underlying type@]@ \
+           %t@]"
+        longident lid main
   | Cannot_implement_parameter path ->
       Location.errorf ~loc
         "@[Interface %s@ found for this unit is flagged as a parameter.@ \

ocaml/typing/typemod.mli

@@ -145,6 +145,7 @@ type error =
   | Unpackable_local_modtype_subst of Path.t
   | With_cannot_remove_packed_modtype of Path.t * module_type
   | Toplevel_nonvalue of string * sort
+  | Strengthening_mismatch of Longident.t * Includemod.explanation
   | Cannot_implement_parameter of Misc.filepath
   | Cannot_pack_parameter
   | Cannot_compile_implementation_as_parameter