anchor.diff:      ./koch tools -d:release
   
       runHook postBuild
  -  '';
  -
  -  prePatch =
  -    let disableTest = ''sed -i '1i discard \"\"\"\n  disabled: true\n\"\"\"\n\n' '';
  -        disableStdLibTest = ''sed -i -e '/^when isMainModule/,/^END$/{s/^/#/}' '';
  -        disableCompile = ''sed -i -e 's/^/#/' '';
  -    in ''
  -      substituteInPlace ./tests/osproc/tworkingdir.nim --replace "/usr/bin" "${coreutils}/bin"
  -      substituteInPlace ./tests/stdlib/ttimes.nim --replace "/usr/share/zoneinfo" "${tzdata}/share/zoneinfo"
  -
  -      # runs out of memory on a machine with 8GB RAM
  -      ${disableTest} ./tests/system/t7894.nim
  -
  -      # requires network access (not available in the build container)
  -      ${disableTest} ./tests/stdlib/thttpclient.nim
  -    '' + lib.optionalString stdenv.isAarch64 ''
  -      # supposedly broken on aarch64
  -      ${disableStdLibTest} ./lib/pure/stats.nim
  -
  -      # reported upstream: https://github.com/nim-lang/Nim/issues/11463
  -      ${disableCompile} ./lib/nimhcr.nim
  -      ${disableTest} ./tests/dll/nimhcr_unit.nim
  -      ${disableTest} ./tests/dll/nimhcr_integration.nim
  -
  -      # reported upstream: https://github.com/nim-lang/Nim/issues/12262
  -      ${disableTest} ./tests/range/tcompiletime_range_checks.nim
  -
  -      # requires "immintrin.h" which is available only on x86
  -      ${disableTest} ./tests/misc/tsizeof3.nim
  -    '';
  -
  -  checkPhase = ''
  -    runHook preCheck
  -
  -    # Fortify hardening breaks tests
  -    # https://github.com/nim-lang/Nim/issues/11435#issuecomment-534545696
  -    NIX_HARDENING_ENABLE=''${NIX_HARDENING_ENABLE/fortify/} \
  -    ./koch tests --nim:bin/nim all
  -
  -    runHook postCheck
     '';
   
     installPhase = ''
  
positive.code:     url = "https://nim-lang.org/download/${pname}-${version}.tar.xz";
      sha256 = "1rjinrs119c8i6wzz5fzjfml7n7kbd5hb9642g4rr8qxkq4sx83k";
    };
  
    doCheck = !stdenv.isDarwin;
  
    enableParallelBuilding = true;
  
  
negative.code: # based on https://github.com/nim-lang/Nim/blob/v0.18.0/.travis.yml
  
  { stdenv, lib, fetchurl, makeWrapper, openssl, pcre, readline,
    boehmgc, sfml, sqlite }:
  
  stdenv.mkDerivation rec {
    pname = "nim";
  