Only enable assert_dep_graph when query-dep-graph is enabled.

compiler/rustc_incremental/src/assert_dep_graph.rs

@@ -57,6 +57,10 @@ pub fn assert_dep_graph(tcx: TyCtxt<'_>) {
             dump_graph(tcx);
         }
 
+        if !tcx.sess.opts.debugging_opts.query_dep_graph {
+            return;
+        }
+
         // if the `rustc_attrs` feature is not enabled, then the
         // attributes we are interested in cannot be present anyway, so
         // skip the walk.

compiler/rustc_incremental/src/persist/dirty_clean.rs

@@ -148,6 +148,10 @@ impl Assertion {
 }
 
 pub fn check_dirty_clean_annotations(tcx: TyCtxt<'_>) {
+    if !tcx.sess.opts.debugging_opts.query_dep_graph {
+        return;
+    }
+
     // can't add `#[rustc_dirty]` etc without opting in to this feature
     if !tcx.features().rustc_attrs {
         return;