lib/tests: Add test case for imports from derivations

lib/tests/modules/import-from-store.nix

@@ -0,0 +1,17 @@
+{ lib, ... }:
+let
+  drv = derivation {
+    name = "derivation";
+    system = builtins.currentSystem;
+    builder = "/bin/sh";
+    args = [ "-c" "echo {} > $out" ];
+  };
+in {
+
+  imports = [
+    "${drv}"
+    ./declare-enable.nix
+    ./define-enable.nix
+  ];
+
+}