If you look in src/mongo/util/stack_introspect.cpp
you'll see this:

if ( method == "MultiPlanScanner" ||
method == "QueryPlan" ||
method == "QueryPlanSet" ||
method == "QueryOptimizerCursorImpl" ||
method == "QueryPlanGenerator" )
return false;

if you remove those lines, you'll get fasserts when running tests

to fix, we can't access data in constructors