tests: Lower default of iters to 4 (but keep higher on CI) #1561

1. 
   real-or-random commented at 4:25 pm on July 1, 2024: contributor

   See discussion at https://gnusha.org/secp256k1/2024-07-01.log, also mentioned in #1549.
2. real-or-random added the label assurance on Jul 1, 2024
3. 
   jonasnick commented at 6:01 pm on July 1, 2024: contributor

   @sipa said the following in the discussion:

   < sipa> i don’t think that running at more than 1 has ever actually contributed to a bug being found :p

   I don’t agree. For example, there are tests that should draw random group elements with an even Y coordinate in one iteration and an odd one in another to test both code paths. Default iteration number of 4 will make 1 in 16 such tests useless.

4. 
   sipa commented at 8:49 pm on July 1, 2024: contributor

   @jonasnick I don’t mean to imply that running with more than 1 iteration doesn’t add anything; it clearly adds cases that aren’t performed otherwise. I literally meant that I don’t think we have ever found an actual bug through those.
5. 
   jonasnick commented at 9:41 pm on July 1, 2024: contributor

   Should have spelled this out more clearly: I have found bugs during development in code that was only correct if the Y coordinates of random group elements had a specific parity :/
6. 
   jonasnick commented at 3:31 pm on October 21, 2024: contributor

   See also https://github.com/bitcoin-core/secp256k1/issues/1036
7. real-or-random closed this on Nov 1, 2024

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8. hebasto referenced this in commit 7d48f5ed02 on Nov 1, 2024

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real-or-random jonasnick sipa

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