Cannot set an RNG (or the seed) while using `forall`

[bhb]

Thanks for a great library!

I'd like to be able to configure the RNG to use the seed pass into Rspec. This would be useful in case my property-based spec fails in CI. I would be able to easily reproduce it by setting the seed manually on my dev machine.

I am currently using forall, which is super convenient for my use case. AFAICT, there is not a way to set the RNG that is used by forall. Additionally, it seems forall might not use the globally configured RNG either.

ruby-prop_check/lib/prop_check/property.rb

Line 334 in 155a327

rng = Random.new

I apologize if I've missed something.