# Copyright 2018 The Meson development team # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # http://www.apache.org/licenses/LICENSE-2.0 # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. from pathlib import Path import functools import json import os import shutil import typing as T from . import ExtensionModule from .. import mesonlib from .. import mlog from ..coredata import UserFeatureOption from ..build import known_shmod_kwargs from ..dependencies import DependencyMethods, PkgConfigDependency, NotFoundDependency, SystemDependency, ExtraFrameworkDependency from ..dependencies.base import process_method_kw from ..environment import detect_cpu_family from ..interpreter import ExternalProgramHolder, extract_required_kwarg, permitted_dependency_kwargs from ..interpreter.type_checking import NoneType from ..interpreterbase import ( noPosargs, noKwargs, permittedKwargs, ContainerTypeInfo, InvalidArguments, typed_pos_args, typed_kwargs, KwargInfo, FeatureNew, FeatureNewKwargs, disablerIfNotFound ) from ..mesonlib import MachineChoice from ..programs import ExternalProgram, NonExistingExternalProgram if T.TYPE_CHECKING: from . import ModuleState from ..build import SharedModule, Data from ..dependencies import ExternalDependency, Dependency from ..dependencies.factory import DependencyGenerator from ..environment import Environment from ..interpreter import Interpreter from ..interpreterbase.interpreterbase import TYPE_var, TYPE_kwargs from typing_extensions import TypedDict mod_kwargs = {'subdir'} mod_kwargs.update(known_shmod_kwargs) mod_kwargs -= {'name_prefix', 'name_suffix'} if T.TYPE_CHECKING: _Base = ExternalDependency else: _Base = object class _PythonDependencyBase(_Base): def __init__(self, python_holder: 'PythonInstallation', embed: bool): self.name = 'python' # override the name from the "real" dependency lookup self.embed = embed self.version: str = python_holder.version self.platform = python_holder.platform self.variables = python_holder.variables self.paths = python_holder.paths self.link_libpython = python_holder.link_libpython self.info: T.Optional[T.Dict[str, str]] = None if mesonlib.version_compare(self.version, '>= 3.0'): self.major_version = 3 else: self.major_version = 2 class PythonPkgConfigDependency(PkgConfigDependency, _PythonDependencyBase): def __init__(self, name: str, environment: 'Environment', kwargs: T.Dict[str, T.Any], installation: 'PythonInstallation'): PkgConfigDependency.__init__(self, name, environment, kwargs) _PythonDependencyBase.__init__(self, installation, kwargs.get('embed', False)) class PythonFrameworkDependency(ExtraFrameworkDependency, _PythonDependencyBase): def __init__(self, name: str, environment: 'Environment', kwargs: T.Dict[str, T.Any], installation: 'PythonInstallation'): ExtraFrameworkDependency.__init__(self, name, environment, kwargs) _PythonDependencyBase.__init__(self, installation, kwargs.get('embed', False)) class PythonSystemDependency(SystemDependency, _PythonDependencyBase): def __init__(self, name: str, environment: 'Environment', kwargs: T.Dict[str, T.Any], installation: 'PythonInstallation'): SystemDependency.__init__(self, name, environment, kwargs) _PythonDependencyBase.__init__(self, installation, kwargs.get('embed', False)) if mesonlib.is_windows(): self._find_libpy_windows(environment) else: self._find_libpy(installation, environment) def _find_libpy(self, python_holder: 'PythonInstallation', environment: 'Environment') -> None: if python_holder.is_pypy: if self.major_version == 3: libname = 'pypy3-c' else: libname = 'pypy-c' libdir = os.path.join(self.variables.get('base'), 'bin') libdirs = [libdir] else: libname = f'python{self.version}' if 'DEBUG_EXT' in self.variables: libname += self.variables['DEBUG_EXT'] if 'ABIFLAGS' in self.variables: libname += self.variables['ABIFLAGS'] libdirs = [] largs = self.clib_compiler.find_library(libname, environment, libdirs) if largs is not None: self.link_args = largs self.is_found = largs is not None or self.link_libpython inc_paths = mesonlib.OrderedSet([ self.variables.get('INCLUDEPY'), self.paths.get('include'), self.paths.get('platinclude')]) self.compile_args += ['-I' + path for path in inc_paths if path] def _get_windows_python_arch(self) -> T.Optional[str]: if self.platform == 'mingw': pycc = self.variables.get('CC') if pycc.startswith('x86_64'): return '64' elif pycc.startswith(('i686', 'i386')): return '32' else: mlog.log(f'MinGW Python built with unknown CC {pycc!r}, please file a bug') return None elif self.platform == 'win32': return '32' elif self.platform in ('win64', 'win-amd64'): return '64' mlog.log(f'Unknown Windows Python platform {self.platform!r}') return None def _get_windows_link_args(self) -> T.Optional[T.List[str]]: if self.platform.startswith('win'): vernum = self.variables.get('py_version_nodot') if self.static: libpath = Path('libs') / f'libpython{vernum}.a' else: comp = self.get_compiler() if comp.id == "gcc": libpath = Path(f'python{vernum}.dll') else: libpath = Path('libs') / f'python{vernum}.lib' # base_prefix to allow for virtualenvs. lib = Path(self.variables.get('base_prefix')) / libpath elif self.platform == 'mingw': if self.static: libname = self.variables.get('LIBRARY') else: libname = self.variables.get('LDLIBRARY') lib = Path(self.variables.get('LIBDIR')) / libname else: raise mesonlib.MesonBugException( 'On a Windows path, but the OS doesn\'t appear to be Windows or MinGW.') if not lib.exists(): mlog.log('Could not find Python3 library {!r}'.format(str(lib))) return None return [str(lib)] def _find_libpy_windows(self, env: 'Environment') -> None: ''' Find python3 libraries on Windows and also verify that the arch matches what we are building for. ''' pyarch = self._get_windows_python_arch() if pyarch is None: self.is_found = False return arch = detect_cpu_family(env.coredata.compilers.host) if arch == 'x86': arch = '32' elif arch == 'x86_64': arch = '64' else: # We can't cross-compile Python 3 dependencies on Windows yet mlog.log(f'Unknown architecture {arch!r} for', mlog.bold(self.name)) self.is_found = False return # Pyarch ends in '32' or '64' if arch != pyarch: mlog.log('Need', mlog.bold(self.name), f'for {arch}-bit, but found {pyarch}-bit') self.is_found = False return # This can fail if the library is not found largs = self._get_windows_link_args() if largs is None: self.is_found = False return self.link_args = largs # Compile args inc_paths = mesonlib.OrderedSet([ self.variables.get('INCLUDEPY'), self.paths.get('include'), self.paths.get('platinclude')]) self.compile_args += ['-I' + path for path in inc_paths if path] # https://sourceforge.net/p/mingw-w64/mailman/message/30504611/ if pyarch == '64' and self.major_version == 2: self.compile_args += ['-DMS_WIN64'] self.is_found = True def python_factory(env: 'Environment', for_machine: 'MachineChoice', kwargs: T.Dict[str, T.Any], methods: T.List[DependencyMethods], installation: 'PythonInstallation') -> T.List['DependencyGenerator']: # We can't use the factory_methods decorator here, as we need to pass the # extra installation argument embed = kwargs.get('embed', False) candidates: T.List['DependencyGenerator'] = [] pkg_version = installation.variables.get('LDVERSION') or installation.version if DependencyMethods.PKGCONFIG in methods: pkg_libdir = installation.variables.get('LIBPC') pkg_embed = '-embed' if embed and mesonlib.version_compare(installation.version, '>=3.8') else '' pkg_name = f'python-{pkg_version}{pkg_embed}' # If python-X.Y.pc exists in LIBPC, we will try to use it def wrap_in_pythons_pc_dir(name: str, env: 'Environment', kwargs: T.Dict[str, T.Any], installation: 'PythonInstallation') -> 'ExternalDependency': old_pkg_libdir = os.environ.pop('PKG_CONFIG_LIBDIR', None) old_pkg_path = os.environ.pop('PKG_CONFIG_PATH', None) if pkg_libdir: os.environ['PKG_CONFIG_LIBDIR'] = pkg_libdir try: return PythonPkgConfigDependency(name, env, kwargs, installation) finally: def set_env(name, value): if value is not None: os.environ[name] = value elif name in os.environ: del os.environ[name] set_env('PKG_CONFIG_LIBDIR', old_pkg_libdir) set_env('PKG_CONFIG_PATH', old_pkg_path) candidates.extend([ functools.partial(wrap_in_pythons_pc_dir, pkg_name, env, kwargs, installation), functools.partial(PythonPkgConfigDependency, pkg_name, env, kwargs, installation) ]) if DependencyMethods.SYSTEM in methods: candidates.append(functools.partial(PythonSystemDependency, 'python', env, kwargs, installation)) if DependencyMethods.EXTRAFRAMEWORK in methods: nkwargs = kwargs.copy() if mesonlib.version_compare(pkg_version, '>= 3'): # There is a python in /System/Library/Frameworks, but that's python 2.x, # Python 3 will always be in /Library nkwargs['paths'] = ['/Library/Frameworks'] candidates.append(functools.partial(PythonFrameworkDependency, 'Python', env, nkwargs, installation)) return candidates INTROSPECT_COMMAND = '''\ import os.path import sysconfig import json import sys import distutils.command.install def get_distutils_paths(scheme=None, prefix=None): import distutils.dist distribution = distutils.dist.Distribution() install_cmd = distribution.get_command_obj('install') if prefix is not None: install_cmd.prefix = prefix if scheme: install_cmd.select_scheme(scheme) install_cmd.finalize_options() return { 'data': install_cmd.install_data, 'include': os.path.dirname(install_cmd.install_headers), 'platlib': install_cmd.install_platlib, 'purelib': install_cmd.install_purelib, 'scripts': install_cmd.install_scripts, } # On Debian derivatives, the Python interpreter shipped by the distribution uses # a custom install scheme, deb_system, for the system install, and changes the # default scheme to a custom one pointing to /usr/local and replacing # site-packages with dist-packages. # See https://github.com/mesonbuild/meson/issues/8739. # XXX: We should be using sysconfig, but Debian only patches distutils. if 'deb_system' in distutils.command.install.INSTALL_SCHEMES: paths = get_distutils_paths(scheme='deb_system') install_paths = get_distutils_paths(scheme='deb_system', prefix='') else: paths = sysconfig.get_paths() empty_vars = {'base': '', 'platbase': '', 'installed_base': ''} install_paths = sysconfig.get_paths(vars=empty_vars) def links_against_libpython(): from distutils.core import Distribution, Extension cmd = Distribution().get_command_obj('build_ext') cmd.ensure_finalized() return bool(cmd.get_libraries(Extension('dummy', []))) variables = sysconfig.get_config_vars() variables.update({'base_prefix': getattr(sys, 'base_prefix', sys.prefix)}) print(json.dumps({ 'variables': variables, 'paths': paths, 'install_paths': install_paths, 'sys_paths': sys.path, 'version': sysconfig.get_python_version(), 'platform': sysconfig.get_platform(), 'is_pypy': '__pypy__' in sys.builtin_module_names, 'link_libpython': links_against_libpython(), })) ''' if T.TYPE_CHECKING: class PythonIntrospectionDict(TypedDict): install_paths: T.Dict[str, str] is_pypy: bool link_libpython: bool paths: T.Dict[str, str] platform: str suffix: str variables: T.Dict[str, str] version: str class PythonExternalProgram(ExternalProgram): def __init__(self, name: str, command: T.Optional[T.List[str]] = None, ext_prog: T.Optional[ExternalProgram] = None): if ext_prog is None: super().__init__(name, command=command, silent=True) else: self.name = name self.command = ext_prog.command self.path = ext_prog.path # We want strong key values, so we always populate this with bogus data. # Otherwise to make the type checkers happy we'd have to do .get() for # everycall, even though we know that the introspection data will be # complete self.info: 'PythonIntrospectionDict' = { 'install_paths': {}, 'is_pypy': False, 'link_libpython': False, 'paths': {}, 'platform': 'sentinal', 'variables': {}, 'version': '0.0', } def _check_version(self, version: str) -> bool: if self.name == 'python2': return mesonlib.version_compare(version, '< 3.0') elif self.name == 'python3': return mesonlib.version_compare(version, '>= 3.0') return True def sanity(self, state: T.Optional['ModuleState'] = None) -> bool: # Sanity check, we expect to have something that at least quacks in tune cmd = self.get_command() + ['-c', INTROSPECT_COMMAND] p, stdout, stderr = mesonlib.Popen_safe(cmd) try: info = json.loads(stdout) except json.JSONDecodeError: info = None mlog.debug('Could not introspect Python (%s): exit code %d' % (str(p.args), p.returncode)) mlog.debug('Program stdout:\n') mlog.debug(stdout) mlog.debug('Program stderr:\n') mlog.debug(stderr) if info is not None and self._check_version(info['version']): variables = info['variables'] info['suffix'] = variables.get('EXT_SUFFIX') or variables.get('SO') or variables.get('.so') self.info = T.cast('PythonIntrospectionDict', info) self.platlib = self._get_path(state, 'platlib') self.purelib = self._get_path(state, 'purelib') return True else: return False def _get_path(self, state: T.Optional['ModuleState'], key: str) -> None: rel_path = self.info['install_paths'][key][1:] if not state: # This happens only from run_project_tests.py return rel_path value = state.get_option(f'{key}dir', module='python') if value: return value # Use python's path relative to prefix, and warn if that's not a location # python will lookup for modules. abs_path = Path(state.get_option('prefix'), rel_path) sys_paths = [Path(i) for i in self.info['sys_paths']] if abs_path not in sys_paths: mlog.warning('Python files installed by Meson might not be found by python interpreter.\n', f'This warning can be avoided by setting "python.{key}dir" option.', once=True) return rel_path _PURE_KW = KwargInfo('pure', bool, default=True) _SUBDIR_KW = KwargInfo('subdir', str, default='') if T.TYPE_CHECKING: class PyInstallKw(TypedDict): pure: bool subdir: str install_tag: T.Optional[str] class PythonInstallation(ExternalProgramHolder): def __init__(self, python: 'PythonExternalProgram', interpreter: 'Interpreter'): ExternalProgramHolder.__init__(self, python, interpreter) info = python.info prefix = self.interpreter.environment.coredata.get_option(mesonlib.OptionKey('prefix')) assert isinstance(prefix, str), 'for mypy' self.variables = info['variables'] self.suffix = info['suffix'] self.paths = info['paths'] self.platlib_install_path = os.path.join(prefix, python.platlib) self.purelib_install_path = os.path.join(prefix, python.purelib) self.version = info['version'] self.platform = info['platform'] self.is_pypy = info['is_pypy'] self.link_libpython = info['link_libpython'] self.methods.update({ 'extension_module': self.extension_module_method, 'dependency': self.dependency_method, 'install_sources': self.install_sources_method, 'get_install_dir': self.get_install_dir_method, 'language_version': self.language_version_method, 'found': self.found_method, 'has_path': self.has_path_method, 'get_path': self.get_path_method, 'has_variable': self.has_variable_method, 'get_variable': self.get_variable_method, 'path': self.path_method, }) @permittedKwargs(mod_kwargs) def extension_module_method(self, args: T.List['TYPE_var'], kwargs: 'TYPE_kwargs') -> 'SharedModule': if 'install_dir' in kwargs: if 'subdir' in kwargs: raise InvalidArguments('"subdir" and "install_dir" are mutually exclusive') else: subdir = kwargs.pop('subdir', '') if not isinstance(subdir, str): raise InvalidArguments('"subdir" argument must be a string.') kwargs['install_dir'] = os.path.join(self.platlib_install_path, subdir) # On macOS and some Linux distros (Debian) distutils doesn't link # extensions against libpython. We call into distutils and mirror its # behavior. See https://github.com/mesonbuild/meson/issues/4117 if not self.link_libpython: new_deps = [] for dep in mesonlib.extract_as_list(kwargs, 'dependencies'): if isinstance(dep, _PythonDependencyBase): dep = dep.get_partial_dependency(compile_args=True) new_deps.append(dep) kwargs['dependencies'] = new_deps # msys2's python3 has "-cpython-36m.dll", we have to be clever # FIXME: explain what the specific cleverness is here split, suffix = self.suffix.rsplit('.', 1) args[0] += split kwargs['name_prefix'] = '' kwargs['name_suffix'] = suffix return self.interpreter.func_shared_module(None, args, kwargs) @disablerIfNotFound @permittedKwargs(permitted_dependency_kwargs | {'embed'}) @FeatureNewKwargs('python_installation.dependency', '0.53.0', ['embed']) @noPosargs def dependency_method(self, args: T.List['TYPE_var'], kwargs: 'TYPE_kwargs') -> 'Dependency': disabled, required, feature = extract_required_kwarg(kwargs, self.subproject) # it's theoretically (though not practically) possible for the else clse # to not bind dep, let's ensure it is. dep: 'Dependency' = NotFoundDependency('python', self.interpreter.environment) if disabled: mlog.log('Dependency', mlog.bold('python'), 'skipped: feature', mlog.bold(feature), 'disabled') else: new_kwargs = kwargs.copy() new_kwargs['required'] = False methods = process_method_kw({DependencyMethods.PKGCONFIG, DependencyMethods.SYSTEM}, kwargs) for d in python_factory(self.interpreter.environment, MachineChoice.BUILD if kwargs.get('native', False) else MachineChoice.HOST, new_kwargs, methods, self): dep = d() if dep.found(): break if required and not dep.found(): raise mesonlib.MesonException('Python dependency not found') return dep @typed_pos_args('install_data', varargs=(str, mesonlib.File)) @typed_kwargs('python_installation.install_sources', _PURE_KW, _SUBDIR_KW, KwargInfo('install_tag', (str, NoneType), since='0.60.0')) def install_sources_method(self, args: T.Tuple[T.List[T.Union[str, mesonlib.File]]], kwargs: 'PyInstallKw') -> 'Data': tag = kwargs['install_tag'] or 'runtime' return self.interpreter.install_data_impl( self.interpreter.source_strings_to_files(args[0]), self._get_install_dir_impl(kwargs['pure'], kwargs['subdir']), mesonlib.FileMode(), rename=None, tag=tag, install_data_type='python', install_dir_name=self._get_install_dir_name_impl(kwargs['pure'], kwargs['subdir'])) @noPosargs @typed_kwargs('python_installation.install_dir', _PURE_KW, _SUBDIR_KW) def get_install_dir_method(self, args: T.List['TYPE_var'], kwargs: 'PyInstallKw') -> str: return self._get_install_dir_impl(kwargs['pure'], kwargs['subdir']) def _get_install_dir_impl(self, pure: bool, subdir: str) -> str: return os.path.join( self.purelib_install_path if pure else self.platlib_install_path, subdir) def _get_install_dir_name_impl(self, pure: bool, subdir: str) -> str: return os.path.join('{py_purelib}' if pure else '{py_platlib}', subdir) @noPosargs @noKwargs def language_version_method(self, args: T.List['TYPE_var'], kwargs: 'TYPE_kwargs') -> str: return self.version @typed_pos_args('python_installation.has_path', str) @noKwargs def has_path_method(self, args: T.Tuple[str], kwargs: 'TYPE_kwargs') -> bool: return args[0] in self.paths @typed_pos_args('python_installation.get_path', str, optargs=[object]) @noKwargs def get_path_method(self, args: T.Tuple[str, T.Optional['TYPE_var']], kwargs: 'TYPE_kwargs') -> 'TYPE_var': path_name, fallback = args try: return self.paths[path_name] except KeyError: if fallback is not None: return fallback raise InvalidArguments(f'{path_name} is not a valid path name') @typed_pos_args('python_installation.has_variable', str) @noKwargs def has_variable_method(self, args: T.Tuple[str], kwargs: 'TYPE_kwargs') -> bool: return args[0] in self.variables @typed_pos_args('python_installation.get_variable', str, optargs=[object]) @noKwargs def get_variable_method(self, args: T.Tuple[str, T.Optional['TYPE_var']], kwargs: 'TYPE_kwargs') -> 'TYPE_var': var_name, fallback = args try: return self.variables[var_name] except KeyError: if fallback is not None: return fallback raise InvalidArguments(f'{var_name} is not a valid variable name') @noPosargs @noKwargs @FeatureNew('Python module path method', '0.50.0') def path_method(self, args: T.List['TYPE_var'], kwargs: 'TYPE_kwargs') -> str: return super().path_method(args, kwargs) if T.TYPE_CHECKING: from ..interpreter.kwargs import ExtractRequired class FindInstallationKw(ExtractRequired): disabler: bool modules: T.List[str] class PythonModule(ExtensionModule): @FeatureNew('Python Module', '0.46.0') def __init__(self, interpreter: 'Interpreter') -> None: super().__init__(interpreter) self.methods.update({ 'find_installation': self.find_installation, }) # https://www.python.org/dev/peps/pep-0397/ @staticmethod def _get_win_pythonpath(name_or_path: str) -> T.Optional[str]: if name_or_path not in ['python2', 'python3']: return None if not shutil.which('py'): # program not installed, return without an exception return None ver = {'python2': '-2', 'python3': '-3'}[name_or_path] cmd = ['py', ver, '-c', "import sysconfig; print(sysconfig.get_config_var('BINDIR'))"] _, stdout, _ = mesonlib.Popen_safe(cmd) directory = stdout.strip() if os.path.exists(directory): return os.path.join(directory, 'python') else: return None @disablerIfNotFound @typed_pos_args('python.find_installation', optargs=[str]) @typed_kwargs( 'python.find_installation', KwargInfo('required', (bool, UserFeatureOption), default=True), KwargInfo('disabler', bool, default=False, since='0.49.0'), KwargInfo('modules', ContainerTypeInfo(list, str), listify=True, default=[], since='0.51.0'), ) def find_installation(self, state: 'ModuleState', args: T.Tuple[T.Optional[str]], kwargs: 'FindInstallationKw') -> ExternalProgram: feature_check = FeatureNew('Passing "feature" option to find_installation', '0.48.0') disabled, required, feature = extract_required_kwarg(kwargs, state.subproject, feature_check) want_modules = kwargs['modules'] found_modules: T.List[str] = [] missing_modules: T.List[str] = [] # FIXME: this code is *full* of sharp corners. It assumes that it's # going to get a string value (or now a list of length 1), of `python2` # or `python3` which is completely nonsense. On windows the value could # easily be `['py', '-3']`, or `['py', '-3.7']` to get a very specific # version of python. On Linux we might want a python that's not in # $PATH, or that uses a wrapper of some kind. np: T.List[str] = state.environment.lookup_binary_entry(MachineChoice.HOST, 'python') or [] fallback = args[0] display_name = fallback or 'python' if not np and fallback is not None: np = [fallback] name_or_path = np[0] if np else None if disabled: mlog.log('Program', name_or_path or 'python', 'found:', mlog.red('NO'), '(disabled by:', mlog.bold(feature), ')') return NonExistingExternalProgram() if not name_or_path: python = PythonExternalProgram('python3', mesonlib.python_command) else: tmp_python = ExternalProgram.from_entry(display_name, name_or_path) python = PythonExternalProgram(display_name, ext_prog=tmp_python) if not python.found() and mesonlib.is_windows(): pythonpath = self._get_win_pythonpath(name_or_path) if pythonpath is not None: name_or_path = pythonpath python = PythonExternalProgram(name_or_path) # Last ditch effort, python2 or python3 can be named python # on various platforms, let's not give up just yet, if an executable # named python is available and has a compatible version, let's use # it if not python.found() and name_or_path in ['python2', 'python3']: python = PythonExternalProgram('python') if python.found() and want_modules: for mod in want_modules: p, *_ = mesonlib.Popen_safe( python.command + ['-c', f'import {mod}']) if p.returncode != 0: missing_modules.append(mod) else: found_modules.append(mod) msg: T.List['mlog.TV_Loggable'] = ['Program', python.name] if want_modules: msg.append('({})'.format(', '.join(want_modules))) msg.append('found:') if python.found() and not missing_modules: msg.extend([mlog.green('YES'), '({})'.format(' '.join(python.command))]) else: msg.append(mlog.red('NO')) if found_modules: msg.append('modules:') msg.append(', '.join(found_modules)) mlog.log(*msg) if not python.found(): if required: raise mesonlib.MesonException('{} not found'.format(name_or_path or 'python')) return NonExistingExternalProgram() elif missing_modules: if required: raise mesonlib.MesonException('{} is missing modules: {}'.format(name_or_path or 'python', ', '.join(missing_modules))) return NonExistingExternalProgram() else: sane = python.sanity(state) if sane: return python else: if required: raise mesonlib.MesonException(f'{python} is not a valid python or it is missing distutils') return NonExistingExternalProgram() raise mesonlib.MesonBugException('Unreachable code was reached (PythonModule.find_installation).') def initialize(interpreter: 'Interpreter') -> PythonModule: mod = PythonModule(interpreter) mod.interpreter.append_holder_map(PythonExternalProgram, PythonInstallation) return mod