_

Signed-off-by: Rudi Grinberg <me@rgrinberg.com>

src/dune_rules/merlin/ocaml_index.ml

@@ -18,27 +18,31 @@ let cctx_rules cctx =
      the typedtree. This step is therefore dependent on all the cmts of those
      definitions are used by all the cmts of modules in this cctx. *)
   let sctx = Compilation_context.super_context cctx in
-  let* additional_libs =
-    let open Resolve.Memo.O in
-    let+ non_compile_libs =
-      (* The indexer relies on the load_path of cmt files. When
-         [implicit_transitive_deps] is set to [false] some necessary paths will
-         be missing.These are passed to the indexer with the `-I` flag.
-
-         The implicit transitive libs correspond to the set:
-         (requires_link \ req_compile) *)
-      let* req_link = Compilation_context.requires_link cctx in
-      let+ req_compile = Compilation_context.requires_compile cctx in
-      List.filter req_link ~f:(fun l -> not (List.exists req_compile ~f:(Lib.equal l)))
-    in
-    Lib_flags.L.include_flags non_compile_libs (Lib_mode.Ocaml Byte)
-  in
   let dir = Compilation_context.dir cctx in
   let aggregate =
     let obj_dir = Compilation_context.obj_dir cctx in
     let fn = index_path_in_obj_dir obj_dir in
     let includes =
-      Resolve.peek additional_libs |> Result.value ~default:Command.Args.empty
+      Command.Args.Dyn
+        (Action_builder.of_memo
+         @@
+         let+ additional_libs =
+           let open Resolve.Memo.O in
+           let+ non_compile_libs =
+             (* The indexer relies on the load_path of cmt files. When
+                [implicit_transitive_deps] is set to [false] some necessary paths will
+                be missing.These are passed to the indexer with the `-I` flag.
+
+                The implicit transitive libs correspond to the set:
+                (requires_link \ req_compile) *)
+             let* req_link = Compilation_context.requires_link cctx in
+             let+ req_compile = Compilation_context.requires_compile cctx in
+             List.filter req_link ~f:(fun l ->
+               not (List.exists req_compile ~f:(Lib.equal l)))
+           in
+           Lib_flags.L.include_flags non_compile_libs (Lib_mode.Ocaml Byte)
+         in
+         Resolve.peek additional_libs |> Result.value ~default:Command.Args.empty)
     in
     let context_dir =
       Compilation_context.context cctx