Troubleshooting¶

sample Returns Null¶

The generator either rejected the sample with filter or ran out of replay bits. Use sampleUnbounded for best-effort generation from an unbounded random source.

Generated Values Are Not Reproducible¶

Use the same generator definition, library version, random seed, and replay tape. Small generator structure changes can change bit consumption and therefore generated values.

foreachMin Throws FailedToMinimizeException¶

The original failure could not be reproduced during minimization. Check whether the property depends on external mutable state, wall-clock time, platform-specific hash codes, or non-deterministic exceptions.

Generated Functions Change Across Platforms¶

Prefer explicit CoGen instances over unsafeFromHashCode when cross-platform stability matters. Platform hashCode behavior can differ for user-defined or mutable objects.

Weighted Choices Reject Options¶

Weighted choices require at least one option and a positive total weight. Integer and double constructors accept zero weights, but not an all-zero set.