Make RNG deterministic again in ssz_generic runner#4642
Merged
jtraglia merged 2 commits intoethereum:masterfrom Oct 7, 2025
Merged
Make RNG deterministic again in ssz_generic runner#4642jtraglia merged 2 commits intoethereum:masterfrom
jtraglia merged 2 commits intoethereum:masterfrom
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With ethereum#4574, the same RNG instance was captured by the various `the_test` functions. When they were subsequently executed in parallel, this led to non-deterministic tests. However, ethereum#4639 prefers reproducible tests. Instead of running tests in parallel on a shared RNG instance, the RNG instance is now used during the single-threaded test collection stage to produce a deterministic order of seeds, which is then used to create a per-test RNG instance that is not shared with any other tests, hence not being subject to non-determinism from parallel execution.
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With #4574, the same RNG instance was captured by the various
the_testfunctions. When they were subsequently executed in parallel, this led to non-deterministic tests. However, #4639 prefers reproducible tests.Instead of running tests in parallel on a shared RNG instance, the RNG instance is now used during the single-threaded test collection stage to produce a deterministic order of seeds, which is then used to create a per-test RNG instance that is not shared with any other tests, hence not being subject to non-determinism from parallel execution.