From 8da7124b8371610ea529b74f200ba937d9c92e6c Mon Sep 17 00:00:00 2001
From: Ali Caglayan <alizter@gmail.com>
Date: Mon, 17 Aug 2026 22:09:34 +0200
Subject: [PATCH] test(package-deps): snapshot template artifact overrides

Record that a scoped package layout preserves a template-defined archive that points to an artifact absent from the layout.

Signed-off-by: Ali Caglayan <alizter@gmail.com>
---
 .../test-cases/package-materialization/dune   |  1 +
 .../template-artifacts.t                      | 39 +++++++++++++++++++
 2 files changed, 40 insertions(+)
 create mode 100644 test/blackbox-tests/test-cases/package-materialization/template-artifacts.t

diff --git a/test/blackbox-tests/test-cases/package-materialization/dune b/test/blackbox-tests/test-cases/package-materialization/dune
index a4dde991d06..df9f41ca40b 100644
--- a/test/blackbox-tests/test-cases/package-materialization/dune
+++ b/test/blackbox-tests/test-cases/package-materialization/dune
@@ -3,5 +3,6 @@
   installed-package
   no-transitive-through-targets
   ocamlfind
+  template-artifacts
   virtual-without-default)
  (deps %{bin:ocamlfind}))
diff --git a/test/blackbox-tests/test-cases/package-materialization/template-artifacts.t b/test/blackbox-tests/test-cases/package-materialization/template-artifacts.t
new file mode 100644
index 00000000000..7cf61e8231b
--- /dev/null
+++ b/test/blackbox-tests/test-cases/package-materialization/template-artifacts.t
@@ -0,0 +1,39 @@
+A META file template can override path-bearing variables without changing the
+library graph. Retaining such a rule while materializing only Dune-selected
+artifacts produces dangling support metadata.
+
+  $ make_dune_project 3.24
+  $ cat >>dune-project <<'EOF'
+  > (package (name artifact-support))
+  > EOF
+
+  $ mkdir support
+  $ cat >support/dune <<'EOF'
+  > (library
+  >  (name artifact_support)
+  >  (public_name artifact-support))
+  > EOF
+  $ echo 'let value = 42' >support/artifact_support.ml
+
+  $ cat >META.artifact-support.template <<'EOF'
+  > # DUNE_GEN
+  > archive(byte,custom) = "missing.cma"
+  > EOF
+
+  $ cat >dune <<'EOF'
+  > (rule
+  >  (target result)
+  >  (deps (package artifact-support))
+  >  (action
+  >   (with-stdout-to %{target}
+  >    (run %{bin:ocamlfind} query -predicates byte,custom -format "%d/%A" artifact-support))))
+  > EOF
+
+The installed META currently retains the conditional archive override even
+though that artifact is not part of the package layout.
+
+  $ dune build result
+  $ cat _build/default/result | censor
+  $PWD/_build/install/default/.packages/$DIGEST/lib/artifact-support/missing.cma
+  $ test -d "$(cat _build/default/result)"
+  [1]