anchor.diff:        problems.
       '';
       license = lib.licenses.bsd3;
  -    maintainers = [ lib.maintainers.ttuegel ];
  +    maintainers = with lib.maintainers; [ ttuegel dotlambda ];
       platforms = lib.platforms.unix;
     };
   }
  
positive.code: 
    cmakeFlags = [
      "-DBUILD_SHARED_LIBS=ON"
      "-DINTERFACE64=${lib.optionalString blas.isILP64 "1"}"
    ];
  
    preCheck = if stdenv.isDarwin then ''
  
negative.code: { lib, stdenv, fetchFromGitHub, fetchpatch, cmake
  , gfortran, blas, lapack, eigen }:
  
  stdenv.mkDerivation rec {
    pname = "arpack";
    version = "3.8.0";
  
    src = fetchFromGitHub {
      owner = "opencollab";
      repo = "arpack-ng";
      rev = version;
      sha256 = "sha256-nc710iLRqy/p3EaVgbEoCRzNJ9GpKqqQp33tbn7R6lA=";
    };
  
    patches = [
      # https://github.com/opencollab/arpack-ng/pull/301
      (fetchpatch {
        name = "pkg-config-paths.patch";
        url = "https://github.com/opencollab/arpack-ng/commit/47fc83cb371a9cc8a8c058097de5e0298cd548f5.patch";
        excludes = [ "CHANGES" ];
        sha256 = "1aijvrfsxkgzqmkzq2dmaj8q3jdpg2hwlqpfl8ddk9scv17gh9m8";
      })
    ];
  
    nativeBuildInputs = [ cmake ];
    buildInputs = assert (blas.isILP64 == lapack.isILP64); [
  