[bobbiechen]

I also found this package: https://github.com/sbyrnes321/numericalunits

Which uses the interesting approach of setting all "units" to random floats: A complete set of independent base units (meters, kilograms, seconds, coulombs, kelvins) are defined as randomly-chosen positive floating-point numbers. All other units and constants are defined in terms of those. In a dimensionally-correct calculation, the units all cancel out, so the final answer is deterministic, not random. In a dimensionally-incorrect calculations, there will be random factors causing a randomly-varying final answer.

Which presumably is done to avoid overhead from carrying around units with each number, but forces you to run calculations multiple times (with different random seeds) to verify the result is correct.