shaderpipeline: Fix unit test failure

panda/src/shaderpipeline/shaderCompiler.cxx

@@ -77,6 +77,10 @@ compile_now(Stage stage, const Filename &fn, BamCacheRecord *record) const {
     }
   }
 
+  if (record2 != nullptr) {
+    record2->add_dependent_file(vf);
+  }
+
   std::istream *in = vf->open_read_file(true);
   if (vf == nullptr) {
     shader_cat.error()