test(pkg): repro 10839 (#10980)

OCaml syntax doesn't work with package management

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

src/dune_rules/dune_file.ml

@@ -463,7 +463,14 @@ module Eval = struct
       let set_dynamic_stanzas = set_dynamic_stanzas ~context in
       let+ ocaml_syntax =
         Memo.parallel_map ocaml_syntax ~f:(fun script ->
-          let+ dune_file, dynamic_includes = Script.eval_one ~context script in
+          let+ dune_file, dynamic_includes =
+            Memo.push_stack_frame
+              ~human_readable_description:(fun () ->
+                Pp.textf
+                  "- evaluating dune file %S in OCaml syntax"
+                  (Path.Source.to_string script.file))
+              (fun () -> Script.eval_one ~context script)
+          in
           set_dynamic_stanzas dune_file ~eval:script.eval ~dynamic_includes)
       in
       let dune_syntax =

test/blackbox-tests/test-cases/pkg/ocaml-syntax-gh10839.t

@@ -0,0 +1,39 @@
+Reproduce #10839.
+
+Dune file in OCaml syntax and a files directory should work
+
+  $ . ./helpers.sh
+
+  $ make_lockdir
+
+  $ make_lockpkg base-bytes <<EOF
+  > (version base)
+  > 
+  > (depends ocamlfind)
+  > EOF
+
+  $ make_lockpkg ocamlfind <<EOF
+  > (version 1)
+  > EOF
+
+  $ cat >dune-project <<EOF
+  > (lang dune 3.16)
+  > EOF
+
+  $ cat >dune <<EOF
+  > (* -*- tuareg -*- *)
+  > let () = Jbuild_plugin.V1.send ""
+  > EOF
+
+  $ dune build
+
+  $ mkdir dune.lock/ocamlfind.files
+  $ touch dune.lock/ocamlfind.files/foo.patch
+
+  $ dune build
+  Error: Dependency cycle between:
+     - evaluating dune file "dune" in OCaml syntax
+  -> _build/_private/default/.pkg/ocamlfind/target/cookie
+  -> - package base-bytes
+  -> - evaluating dune file "dune" in OCaml syntax
+  [1]