Comment by aw1621107

> Not being able to exhaustively test simple problem absolutely means you can't exhaustively test massively more complex problem.

"Simple"/"complex" doesn't necessarily imply "small"/"large", respectively. Testing whether the Collatz conjecture holds is "simple", but its search space is (potentially) infinitely large. Testing correctness of concurrent data structures is (probably) a more "complex" problem, and yet it's still possible to perform exhaustive tests of their functionality [0].

In the end, the practicality of exhausting the 64-bit integer search space is irrelevant since it says nothing about the size of the write + checkpoint search space. I could just as easily say that it's easy to exhaust the 16-bit integer search space, but that doesn't mean exhaustively testing for this particular bug is easy.

[0]: http://demsky.eecs.uci.edu/publications/c11modelcheck.pdf