Reproduce issue #1867

tests/dune

@@ -1,8 +1,10 @@
-(env (_
- (binaries merlin-wrapper)
- (env-vars
-  (MERLIN merlin-wrapper)
-  (OCAMLC ocamlc))))
+(env
+ (_
+  (binaries merlin-wrapper)
+  (env-vars
+   (MERLIN merlin-wrapper)
+   (OCAMLC ocamlc)
+   (DUNE dune))))
 
 (cram
  (package merlin)
@@ -15,4 +17,5 @@
 
 (cram
  (applies_to with-ppx)
- (deps (package ppxlib)))
+ (deps
+  (package ppxlib)))

tests/test-dirs/issue1867.t

@@ -0,0 +1,28 @@
+  $ cat >dune-project <<'EOF'
+  > (lang dune 3.0)
+  > EOF
+
+  $ cat >dune <<'EOF'
+  > (executable (name foo))
+  > (executable (name foobar) (libraries yojson))
+  > EOF
+
+  $ touch foo.ml 
+
+  $ cat >foobar.ml <<'EOF'
+  > let eq = Yojson.equal
+  > let () = Printf.printf "%b" @@ eq `Null `Null
+  > EOF
+
+  $ $DUNE build 
+  $ $DUNE exec ./foobar.exe
+  true
+
+FIXME: there appear to be an issue with configuration here
+  $ $MERLIN single locate -position 1:10 \
+  > -filename foobar.ml <foobar.ml 
+  {
+    "class": "return",
+    "value": "Not in environment 'Yojson'",
+    "notifications": []
+  }