What if the software is so buggy it can't be tested at all?

In this situation the best bet is to have test engineers go through the process of reporting whatever bugs or problems initially show up, with the focus being on critical bugs. Since this type of problem can severely affect schedules and indicates deeper problems in the software development process, such as insufficient unit testing, insufficient integration testing, poor design, improper build or release procedures, managers should be notified and provided with some documentation as evidence of the problem.