test: Add repro case for ocaml#6153

Signed-off-by: Etienne Millon <[email protected]>

test/blackbox-tests/test-cases/github6153.t

@@ -0,0 +1,42 @@
+  $ cat > ./dune-project << EOF
+  > (lang dune 2.9)
+  > (package (name pub))
+  > EOF
+
+  $ cat > dune << EOF
+  > (library
+  >  (public_name pub)
+  >  (modules pub)
+  >  (libraries priv))
+  > 
+  > (library
+  >  (name priv)
+  >  (modules priv)
+  >  (package pub)
+  >  (libraries dep))
+  > 
+  > (library
+  >  (name dep)
+  >  (modules dep))
+  > EOF
+
+  $ touch {pub,priv,dep}.ml
+
+  $ mkdir bin
+
+  $ cat > ./bin/dune-project << EOF
+  > (lang dune 2.9)
+  > EOF
+
+  $ cat > ./bin/dune << EOF
+  > (executable
+  >  (name prog)
+  >  (libraries pub))
+  > EOF
+
+  $ touch ./bin/prog.ml
+
+  $ dune build 2>&1 | head -n 3
+  Internal error, please report upstream including the contents of _build/log.
+  Description:
+    ("Unexpected find result", { found = Not_found; lib.name = "dep" })