When your scale is large enough, you move to "what monitoring methodology will find this?"
When you're doing enough transactions you start to see a noise floor of e.g. bit flips from cosmic rays, and looking for issues involves correlating/categorizing possible software failures and distinguishing them from the misbehavior of hardware.
I meant, what testing methodology could the compiler writers have used, so it was caught before it went to users.
The feedback loop here should be: novel bug comes in ==> determine how existing testing was deficient ==> modify the testing in a general way that would have found this bug ==> run these modified tests in the background to see if anything similar was missed. Bugs should be used as indicators that regions (as large as possible) of bug space have been inadequately covered.
When you're doing enough transactions you start to see a noise floor of e.g. bit flips from cosmic rays, and looking for issues involves correlating/categorizing possible software failures and distinguishing them from the misbehavior of hardware.