[bug]: Random.seed(rng::StableRNGs, seed::Integer) not working properly

[Fe-r-oz]

Hi Folks,

We want to use StableRNGs for stable streams but there is the following bug:

Random.Seed! using StableRNGs does not work

This gives me a different answer everytime.

julia> using Random

julia> using QuantumClifford

julia> using StableRNGs

julia> rng = StableRNG(42);

julia> Random.seed!(rng, 729);

julia> random_clifford(2)
X₁ ⟼ - YZ
X₂ ⟼ - XX
Z₁ ⟼ - X_
Z₂ ⟼ - _Z

Random.Seed! using Random works

This is static and fine.

julia> using Random

julia> using QuantumClifford

julia> Random.seed!(42);

julia> random_clifford(2)
X₁ ⟼ - YY
X₂ ⟼ - _Y
Z₁ ⟼ + ZY
Z₂ ⟼ + XX

Thanks for the help!

[ericphanson]

That code isn’t doing what you think; when you seed an rng object (StableRNGs or otherwise) it only affect that specific rng object. You can’t change the global rng in Julia. So the only way to use StableRNGs is to pass the rng object into functions that accept an rng instead of only allowing the global rng.

I’ll close this issue since we can’t change how that works here but feel free to ask if you have questions, here or on http://discourse.julialang.org/.

[Fe-r-oz]

My bad! Indeed! random_clifford(rng, 2) working nicely!