test: Sibling modules should be accessible from qualified parsers

test/blackbox-tests/test-cases/menhir/include-subdirs-siblings.t/dune

@@ -0,0 +1,4 @@
+(include_subdirs qualified)
+
+(executable
+ (name foo))

test/blackbox-tests/test-cases/menhir/include-subdirs-siblings.t/dune-project

@@ -0,0 +1,2 @@
+(lang dune 3.14)
+(using menhir 2.1)

test/blackbox-tests/test-cases/menhir/include-subdirs-siblings.t/foo.ml

@@ -0,0 +1,2 @@
+let () =
+  assert (Lang.Parser.expr (fun _ -> Lang.Parser.EOF) (Lexing.from_string "") = Lang.Ast.Unit)

test/blackbox-tests/test-cases/menhir/include-subdirs-siblings.t/lang/ast.ml

@@ -0,0 +1,2 @@
+type expr =
+  | Unit

test/blackbox-tests/test-cases/menhir/include-subdirs-siblings.t/lang/dune

@@ -0,0 +1,2 @@
+(menhir
+ (modules parser))

test/blackbox-tests/test-cases/menhir/include-subdirs-siblings.t/lang/parser.mly

@@ -0,0 +1,8 @@
+%token EOF
+
+%start <Ast.expr> expr
+
+%%
+
+expr:
+| EOF { Ast.Unit }

test/blackbox-tests/test-cases/menhir/include-subdirs-siblings.t/run.t

@@ -0,0 +1,6 @@
+Menhir parsers in qualified subdirectories should be able to refer to sibling modules:
+
+  $ dune build
+  File "lang/parser.mly", line 3, characters 8-16:
+  Error: Unbound module Ast
+  [1]