Unable to Build numpy because of cpu compile flags?

Okay, i’m trying to build my system from scratch (still with glibc, but will try with musl when I can move around my errors more…)
i have these config options:

  nix.settings.system-features = [
    "big-parallel"
    "gccarch-znver3"
  ];
  nixpkgs.hostPlatform = {
    system = "x86_64-linux";
    #  config = "x86_64-unknown-linux-musl";
    gcc.arch = "znver3";
    gcc.tune = "znver3";
  };

and get this error when building numpy:


-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
=========================== short test summary info ============================
FAILED lib/python3.11/site-packages/numpy/core/tests/test_umath_accuracy.py::TestAccuracy::test_validate_transcendentals - AssertionError: Arrays are not almost equal up to 2 ULP (max difference is ...
= 1 failed, 36806 passed, 1614 skipped, 31 xfailed, 3 xpassed, 455 warnings in 208.43s (0:03:28) =
/nix/store/355y2jqjc7yq9qk9h1c8a09hg1dld1p4-stdenv-linux/setup: line 1579: pop_var_context: head of shell_variables not a function context

on flake enabled nixos-24.05-small chanell.

I’m not sure what package requires numpy, I searched a little and found out that python versions and dependencies can be a pain in nixos…

the package i’m building and failing specifically is: this numpy; reading it’s source, it has some checks skipped for specific cpus and looking some people with similar objectives they were recommended an overlay…

i wouldn’t like an overrlay, but if there is no other way how would i do one that works for all python packages?

I found this How to skip some checks? - #3 by Thiago-Assis-T and i’m still trying to find a way without making an overaly, but it doesn’t look like it is possible…

found this issue as well: pythonPackages.numpy test failure: AssertionError: Arrays are not almost equal up to 2 ULP (max difference is 3 ULP) · Issue #275626 · NixOS/nixpkgs · GitHub and kinda get the why it is happening… Can someone explain this better to me?