Reproducible runs

According to the Python documentation it is necessary to set the environment variable PYTHONHASHSEED=0 in order to achieve a truly deterministic behaviour and computation. Furthermore, it is necessary to set the --seed command-line option to a fixed value. If no --seed option was set, Pynguin chooses a seed at random and logs its value.

Note

Using a certain amount of wall-clock time as the stopping condition (MAX_TIME) for Pynguin’s executions can make achieving deterministic results difficult, because Pynguin might achieve slightly different amounts of iterations in each execution. To solve this problem, take note of the amount of achieved iterations in the first execution and use them as the new stopping condition (MAX_ITERATIONS) in a reproduction run, together with the previously used seed. The amount of iterations can be obtained from stdout (when using -v for verbose output) or from the tracked statistics, when tracking the variable AlgorithmIterations.