core/pkgs/by-name/py/python/python2/mk-python-derivation.nix

# Generic builder only used for EOL and deprecated Python 2.

{
  lib,
  config,
  python,
  wrapPython,
  unzip,
  ensureNewerSourcesForZipFilesHook,
  # Whether the derivation provides a Python module or not.
  toPythonModule,
  namePrefix,
  update-python-libraries,
  setuptools,
  pipBuildHook,
  pipInstallHook,
  pythonCatchConflictsHook,
  pythonImportsCheckHook,
  pythonOutputDistHook,
  pythonRemoveBinBytecodeHook,
  pythonRemoveTestsDirHook,
  setuptoolsBuildHook,
  setuptoolsCheckHook,
  wheelUnpackHook,
  eggUnpackHook,
  eggBuildHook,
  eggInstallHook,
}:

{
  name ? "${attrs.pname}-${attrs.version}",

  # Build-time dependencies for the package
  nativeBuildInputs ? [ ],

  # Run-time dependencies for the package
  buildInputs ? [ ],

  # Dependencies needed for running the checkPhase.
  # These are added to buildInputs when doCheck = true.
  checkInputs ? [ ],
  nativeCheckInputs ? [ ],

  # propagate build dependencies so in case we have A -> B -> C,
  # C can import package A propagated by B
  propagatedBuildInputs ? [ ],

  # DEPRECATED: use propagatedBuildInputs
  pythonPath ? [ ],

  # Enabled to detect some (native)BuildInputs mistakes
  strictDeps ? true,

  outputs ? [ "out" ],

  # used to disable derivation, useful for specific python versions
  disabled ? false,

  # Raise an error if two packages are installed with the same name
  # TODO: For cross we probably need a different PYTHONPATH, or not
  # add the runtime deps until after buildPhase.
  catchConflicts ? (python.stdenv.hostPlatform == python.stdenv.buildPlatform),

  # Additional arguments to pass to the makeWrapper function, which wraps
  # generated binaries.
  makeWrapperArgs ? [ ],

  # Skip wrapping of python programs altogether
  dontWrapPythonPrograms ? false,

  # Don't use Pip to install a wheel
  # Note this is actually a variable for the pipInstallPhase in pip's setupHook.
  # It's included here to prevent an infinite recursion.
  dontUsePipInstall ? false,

  # Skip setting the PYTHONNOUSERSITE environment variable in wrapped programs
  permitUserSite ? false,

  # Remove bytecode from bin folder.
  # When a Python script has the extension `.py`, bytecode is generated
  # Typically, executables in bin have no extension, so no bytecode is generated.
  # However, some packages do provide executables with extensions, and thus bytecode is generated.
  removeBinBytecode ? true,

  # Several package formats are supported.
  # "setuptools" : Install a common setuptools/distutils based package. This builds a wheel.
  # "wheel" : Install from a pre-compiled wheel.
  # "pyproject": Install a package using a ``pyproject.toml`` file (PEP517). This builds a wheel.
  # "egg": Install a package from an egg.
  # "other" : Provide your own buildPhase and installPhase.
  format ? "setuptools",

  meta ? { },

  passthru ? { },

  doCheck ? config.doCheckByDefault or false,

  disabledTestPaths ? [ ],

  ...
}@attrs:

let
  inherit (python) stdenv;

  withDistOutput = lib.elem format [
    "pyproject"
    "setuptools"
    "wheel"
  ];

  name_ = name;

  validatePythonMatches =
    attrName:
    let
      isPythonModule =
        drv:
        # all pythonModules have the pythonModule attribute
        (drv ? "pythonModule")
        # Some pythonModules are turned in to a pythonApplication by setting the field to false
        && (!builtins.isBool drv.pythonModule);
      isMismatchedPython = drv: drv.pythonModule != python;

      optionalLocation =
        let
          pos = builtins.unsafeGetAttrPos (if attrs ? "pname" then "pname" else "name") attrs;
        in
        lib.optionalString (pos != null) " at ${pos.file}:${toString pos.line}:${toString pos.column}";

      leftPadName =
        name: against:
        let
          len = lib.max (lib.stringLength name) (lib.stringLength against);
        in
        lib.strings.fixedWidthString len " " name;

      throwMismatch =
        drv:
        let
          myName = "'${namePrefix}${name}'";
          theirName = "'${drv.name}'";
        in
        throw ''
          Python version mismatch in ${myName}:

          The Python derivation ${myName} depends on a Python derivation
          named ${theirName}, but the two derivations use different versions
          of Python:

              ${leftPadName myName theirName} uses ${python}
              ${leftPadName theirName myName} uses ${toString drv.pythonModule}

          Possible solutions:

            * If ${theirName} is a Python library, change the reference to ${theirName}
              in the ${attrName} of ${myName} to use a ${theirName} built from the same
              version of Python

            * If ${theirName} is used as a tool during the build, move the reference to
              ${theirName} in ${myName} from ${attrName} to nativeBuildInputs

            * If ${theirName} provides executables that are called at run time, pass its
              bin path to makeWrapperArgs:

                  makeWrapperArgs = [ "--prefix PATH : ''${lib.makeBinPath [ ${lib.getName drv} ] }" ];

          ${optionalLocation}
        '';

      checkDrv = drv: if (isPythonModule drv) && (isMismatchedPython drv) then throwMismatch drv else drv;

    in
    inputs: builtins.map (checkDrv) inputs;

  # Keep extra attributes from `attrs`, e.g., `patchPhase', etc.
  self = toPythonModule (
    stdenv.mkDerivation (
      (builtins.removeAttrs attrs [
        "disabled"
        "checkPhase"
        "checkInputs"
        "nativeCheckInputs"
        "doCheck"
        "doInstallCheck"
        "dontWrapPythonPrograms"
        "catchConflicts"
        "format"
        "disabledTestPaths"
        "outputs"
      ])
      // {

        name = namePrefix + name_;

        nativeBuildInputs =
          [
            python
            wrapPython
            ensureNewerSourcesForZipFilesHook # move to wheel installer (pip) or builder (setuptools, ...)?
            pythonRemoveTestsDirHook
          ]
          ++ lib.optionals catchConflicts [ pythonCatchConflictsHook ]
          ++ lib.optionals removeBinBytecode [ pythonRemoveBinBytecodeHook ]
          ++ lib.optionals (lib.hasSuffix "zip" (attrs.src.name or "")) [ unzip ]
          ++ lib.optionals (format == "setuptools") [ setuptoolsBuildHook ]
          ++ lib.optionals (format == "pyproject") [ (pipBuildHook) ]
          ++ lib.optionals (format == "wheel") [ wheelUnpackHook ]
          ++ lib.optionals (format == "egg") [
            eggUnpackHook
            eggBuildHook
            eggInstallHook
          ]
          ++ lib.optionals (format != "other") [ (pipInstallHook) ]
          ++ lib.optionals (stdenv.buildPlatform == stdenv.hostPlatform) [
            # This is a test, however, it should be ran independent of the checkPhase and checkInputs
            pythonImportsCheckHook
          ]
          ++ lib.optionals withDistOutput [ pythonOutputDistHook ]
          ++ nativeBuildInputs;

        buildInputs = validatePythonMatches "buildInputs" (buildInputs ++ pythonPath);

        propagatedBuildInputs = validatePythonMatches "propagatedBuildInputs" (
          propagatedBuildInputs
          ++ [
            # we propagate python even for packages transformed with 'toPythonApplication'
            # this pollutes the PATH but avoids rebuilds
            # see https://github.com/NixOS/nixpkgs/issues/170887 for more context
            python
          ]
        );

        inherit strictDeps;

        LANG = "${if python.stdenv.isDarwin then "en_US" else "C"}.UTF-8";

        # Python packages don't have a checkPhase, only an installCheckPhase
        doCheck = false;
        doInstallCheck = attrs.doCheck or true;
        nativeInstallCheckInputs =
          [ ]
          ++ lib.optionals (format == "setuptools") [
            # Longer-term we should get rid of this and require
            # users of this function to set the `installCheckPhase` or
            # pass in a hook that sets it.
            setuptoolsCheckHook
          ]
          ++ nativeCheckInputs;
        installCheckInputs = checkInputs;

        postFixup =
          lib.optionalString (!dontWrapPythonPrograms) ''
            wrapPythonPrograms
          ''
          + attrs.postFixup or "";

        # Python packages built through cross-compilation are always for the host platform.
        disallowedReferences = lib.optionals (python.stdenv.hostPlatform != python.stdenv.buildPlatform) [
          python.pythonOnBuildForHost
        ];

        outputs = outputs ++ lib.optional withDistOutput "dist";

        meta = {
          # default to python's platforms
          platforms = python.meta.platforms;
          isBuildPythonPackage = python.meta.platforms;
        } // meta;
      }
      // lib.optionalAttrs (attrs ? checkPhase) {
        # If given use the specified checkPhase, otherwise use the setup hook.
        # Longer-term we should get rid of `checkPhase` and use `installCheckPhase`.
        installCheckPhase = attrs.checkPhase;
      }
      // lib.optionalAttrs (disabledTestPaths != [ ]) {
        disabledTestPaths = lib.escapeShellArgs disabledTestPaths;
      }
    )
  );

  passthru.updateScript =
    let
      filename = builtins.head (lib.splitString ":" self.meta.position);
    in
    attrs.passthru.updateScript or [
      update-python-libraries
      filename
    ];
in
lib.extendDerivation (
  disabled -> throw "${name} not supported for interpreter ${python.executable}"
) passthru self