Add reproduction test case for #10149.

Signed-off-by: Rodolphe Lepigre <rodolphe@bedrocksystems.com>
Signed-off-by: Ali Caglayan <alizter@gmail.com>

test/blackbox-tests/test-cases/coq/no-rebuild-on-dep-change.t

@@ -0,0 +1,18 @@
+  $ echo "(coq.theory (name bug) (mode vo))" > dune
+  $ echo "(lang dune 3.12)" > dune-project
+  $ echo "(using coq 0.8)" >> dune-project
+  $ touch root.v leaf.v
+  $ dune build
+  $ find _build -name "*.vo" | sort
+  _build/default/leaf.vo
+  _build/default/root.vo
+  $ echo "Require Import bug.root." >> leaf.v
+
+This test makes sure that a full rebuild is not triggered when the output of
+coqdep is changed.
+
+Currently this is the case and a bug:
+  $ dune build --display=short
+        coqdep .bug.theory.d
+          coqc root.{glob,vo}
+          coqc leaf.{glob,vo}