As practice has shown, troubleshooting Query AFs could be troublesome due to very limited diagnostic information, which doesn't even include the failing query. To improve this situation we can dump the entire CurOp instance when a tassert is triggered. This can be achieved either by introducing a new API (e.g., tassertWithDebug) or by changing the call sites to implement it as

if (bad thing) { dump(); tasserted(); }