anchor.diff:  { lib, stdenv
   , fetchFromGitHub
  -, fetchurl
  +, fetchpatch
   , autoreconfHook
   , pkg-config
   , flint
  
positive.code:   nativeBuildInputs = [
      autoreconfHook
      pkg-config
    ];
  
    patches = [
      (fetchurl {
        name = "py_ssize_t_clean.patch";
        url = "https://git.sagemath.org/sage.git/plain/build/pkgs/pynac/patches/py_ssize_t_clean.patch?h=9.2";
        sha256 = "0l3gbg9hc4v671zf4w376krnk3wh8hj3649610nlvzzxckcryzab";
      })
    ];
  
    meta = with lib; {
  
negative.code: }:
  
  stdenv.mkDerivation rec {
    version = "0.7.27";
    pname = "pynac";
  
    src = fetchFromGitHub {
      owner = "pynac";
      repo = "pynac";
      rev = "pynac-${version}";
      sha256 = "sha256-1HHCIeaNE2UsJNX92UlDGLJS8I4nC/8FnwX7Y4F9HpU=";
    };
  
    patches = [
      (fetchpatch {
        name = "handle_factor.patch";
        url = "https://git.sagemath.org/sage.git/plain/build/pkgs/pynac/patches/handle_factor.patch?h=9.3.rc3";
        sha256 = "sha256-U1lb5qwBqZZgklfDMhBX4K5u8bz5x42O4w7hyNy2YVw=";
      })
  
      (fetchpatch {
        name = "power_inf_loop.patch";
        url = "https://git.sagemath.org/sage.git/plain/build/pkgs/pynac/patches/power_inf_loop.patch?h=9.3.rc3";
        sha256 = "sha256-VYeaJl8u2wl7FQ/6xnpZv1KpdNYEmJoPhuMrBADyTRs=";
      })
  
      (fetchpatch {
        name = "too_much_sub.patch";
        url = "https://git.sagemath.org/sage.git/plain/build/pkgs/pynac/patches/too_much_sub.patch?h=9.3.rc3";
        sha256 = "sha256-lw7xSQ/l+rzPu+ghWF4omYF0mKksGGPuuHJTktvbdis=";
      })
    ];
  
    buildInputs = [
      flint
  