Auto merge of #83314 - Aaron1011:print-unstable-value, r=lcnr

Debug-print result when an unstable fingerprint is detected

Helps with issues like #83311

I had previously tried to do this in #80692, but it had a significant performance impact (even though the code was never actually run). Hopefully, this will be better now that #79100 has been merged.

compiler/rustc_query_system/src/query/plumbing.rs

@@ -590,7 +590,7 @@ fn incremental_verify_ich<CTX, K, V: Debug>(
 
     let old_hash = tcx.dep_graph().fingerprint_of(dep_node_index);
 
-    assert!(new_hash == old_hash, "found unstable fingerprints for {:?}", dep_node,);
+    assert!(new_hash == old_hash, "found unstable fingerprints for {:?}: {:?}", dep_node, result);
 }
 
 fn force_query_with_job<C, CTX>(