python2Packages.numpy: fix build on darwin

By applying the old patch (compatible with 1.18.x and older). Also
refactor expression to make presence of the "old" version more
explicit.

pkgs/development/python-modules/numpy/1.16.nix

@@ -0,0 +1,94 @@
+{ lib
+, fetchPypi
+, python
+, buildPythonPackage
+, gfortran
+, pytest
+, blas
+, lapack
+, writeTextFile
+, isPyPy
+, cython
+, setuptoolsBuildHook
+ }:
+
+assert (!blas.isILP64) && (!lapack.isILP64);
+
+let
+  cfg = writeTextFile {
+    name = "site.cfg";
+    text = (lib.generators.toINI {} {
+      ${blas.implementation} = {
+        include_dirs = "${lib.getDev blas}/include:${lib.getDev lapack}/include";
+        library_dirs = "${blas}/lib:${lapack}/lib";
+        libraries = "lapack,lapacke,blas,cblas";
+      };
+      lapack = {
+        include_dirs = "${lib.getDev lapack}/include";
+        library_dirs = "${lapack}/lib";
+      };
+      blas = {
+        include_dirs = "${lib.getDev blas}/include";
+        library_dirs = "${blas}/lib";
+      };
+    });
+  };
+in buildPythonPackage rec {
+  pname = "numpy";
+  version = "1.16.5";
+  format = "pyproject.toml";
+
+  src = fetchPypi {
+    inherit pname version;
+    extension = "zip";
+    sha256 = "8bb452d94e964b312205b0de1238dd7209da452343653ab214b5d681780e7a0c";
+  };
+
+  nativeBuildInputs = [ gfortran pytest cython setuptoolsBuildHook ];
+  buildInputs = [ blas lapack ];
+
+  patches = lib.optionals python.hasDistutilsCxxPatch [
+    # We patch cpython/distutils to fix https://bugs.python.org/issue1222585
+    # Patching of numpy.distutils is needed to prevent it from undoing the
+    # patch to distutils.
+    ./numpy-distutils-C++_1.16.patch
+  ];
+
+  preConfigure = ''
+    sed -i 's/-faltivec//' numpy/distutils/system_info.py
+    export NPY_NUM_BUILD_JOBS=$NIX_BUILD_CORES
+  '';
+
+  preBuild = ''
+    ln -s ${cfg} site.cfg
+  '';
+
+  enableParallelBuilding = true;
+
+  doCheck = !isPyPy; # numpy 1.16+ hits a bug in pypy's ctypes, using either numpy or pypy HEAD fixes this (https://github.com/numpy/numpy/issues/13807)
+
+  checkPhase = ''
+    runHook preCheck
+    pushd dist
+    ${python.interpreter} -c 'import numpy; numpy.test("fast", verbose=10)'
+    popd
+    runHook postCheck
+  '';
+
+  passthru = {
+    # just for backwards compatibility
+    blas = blas.provider;
+    blasImplementation = blas.implementation;
+    inherit cfg;
+  };
+
+  # Disable test
+  # - test_large_file_support: takes a long time and can cause the machine to run out of disk space
+  NOSE_EXCLUDE="test_large_file_support";
+
+  meta = {
+    description = "Scientific tools for Python";
+    homepage = "https://numpy.org/";
+    maintainers = with lib.maintainers; [ fridh ];
+  };
+}