nixpkgs/pkgs/development/python-modules/bootstrapped-pip/default.nix

{ lib, stdenv, python, fetchPypi, makeWrapper, unzip, makeSetupHook
, pipInstallHook
, setuptoolsBuildHook
, wheel, pip, setuptools
, isPy27
}:

stdenv.mkDerivation rec {
  pname = "pip";
  inherit (pip) version;
  name = "${python.libPrefix}-bootstrapped-${pname}-${version}";

  srcs = [ wheel.src pip.src setuptools.src ];
  sourceRoot = ".";

  dontUseSetuptoolsBuild = true;
  dontUsePipInstall = true;

  # Should be propagatedNativeBuildInputs
  propagatedBuildInputs = [
    # Override to remove dependencies to prevent infinite recursion.
    (pipInstallHook.override{pip=null;})
    (setuptoolsBuildHook.override{setuptools=null; wheel=null;})
  ];

  postPatch = ''
    mkdir -p $out/bin
  '';

  nativeBuildInputs = [ makeWrapper unzip ];
  buildInputs = [ python ];

  buildPhase = ":";

  installPhase = lib.strings.optionalString (!stdenv.hostPlatform.isWindows) ''
    export SETUPTOOLS_INSTALL_WINDOWS_SPECIFIC_FILES=0
  '' + ''
    # Give folders a known name
    mv pip* pip
    mv setuptools* setuptools
    mv wheel* wheel
    # Set up PYTHONPATH. The above folders need to be on PYTHONPATH
    # $out is where we are installing to and takes precedence
    export PYTHONPATH="$out/${python.sitePackages}:$(pwd)/pip/src:$(pwd)/setuptools:$(pwd)/setuptools/pkg_resources:$(pwd)/wheel:$PYTHONPATH"

    echo "Building setuptools wheel..."
    pushd setuptools
    ${python.pythonForBuild.interpreter} -m pip install --no-build-isolation --no-index --prefix=$out  --ignore-installed --no-dependencies --no-cache .
    popd

    echo "Building wheel wheel..."
    pushd wheel
    ${python.pythonForBuild.interpreter} -m pip install --no-build-isolation --no-index --prefix=$out  --ignore-installed --no-dependencies --no-cache .
    popd

    echo "Building pip wheel..."
    pushd pip
    ${python.pythonForBuild.interpreter} -m pip install --no-build-isolation --no-index --prefix=$out  --ignore-installed --no-dependencies --no-cache .
    popd
  '';

  meta = {
    description = "Version of pip used for bootstrapping";
    license = lib.unique (pip.meta.license ++ setuptools.meta.license ++ wheel.meta.license);
    homepage = pip.meta.homepage;
  };
}