[macro] add failing macro to 'Build failure' error

src/typing/typeloadFields.ml

@@ -402,7 +402,7 @@ let build_module_def ctx mt meta fvars fbuild =
 				let r = try ctx.g.do_macro ctx MBuild cpath meth el p with e -> ctx.c.get_build_infos <- old; raise e in
 				ctx.c.get_build_infos <- old;
 				(match r with
-				| MError | MMacroInMacro -> raise_typing_error "Build failure" p
+				| MError | MMacroInMacro -> raise_typing_error (Printf.sprintf "Build failure (%s.%s)" (s_type_path cpath) meth) p
 				| MSuccess e -> fbuild e)
 			) :: f_build
 		| _ ->