... until the cause is really and truly a non-deterministic build. Trust me, been there. For a long-ago example: I worked on a project that had an optimizer th

... until the cause is really and truly a non-deterministic build. Trust me, been there. For a long-ago example: I worked on a project that had an optimizer that used time-bounded simulated annealing to optimize. No two builds ever the same. It was "great".