diff --git a/changelog.d/2306.change.rst b/changelog.d/2306.change.rst new file mode 100644 index 0000000000..1046eae3f8 --- /dev/null +++ b/changelog.d/2306.change.rst @@ -0,0 +1,3 @@ +When running as a PEP 517 backend, setuptools does not try to install +``setup_requires`` itself. They are reported as build requirements for the +frontend to install. diff --git a/setuptools/build_meta.py b/setuptools/build_meta.py index 46266814ad..371321879a 100644 --- a/setuptools/build_meta.py +++ b/setuptools/build_meta.py @@ -75,6 +75,22 @@ def patch(cls): distutils.core.Distribution = orig +@contextlib.contextmanager +def no_install_setup_requires(): + """Temporarily disable installing setup_requires + + Under PEP 517, the backend reports build dependencies to the frontend, + and the frontend is responsible for ensuring they're installed. + So setuptools (acting as a backend) should not try to install them. + """ + orig = setuptools._install_setup_requires + setuptools._install_setup_requires = lambda attrs: None + try: + yield + finally: + setuptools._install_setup_requires = orig + + def _to_str(s): """ Convert a filename to a string (on Python 2, explicitly @@ -154,7 +170,8 @@ def prepare_metadata_for_build_wheel(self, metadata_directory, config_settings=None): sys.argv = sys.argv[:1] + ['dist_info', '--egg-base', _to_str(metadata_directory)] - self.run_setup() + with no_install_setup_requires(): + self.run_setup() dist_info_directory = metadata_directory while True: @@ -194,7 +211,8 @@ def _build_with_temp_dir(self, setup_command, result_extension, sys.argv = (sys.argv[:1] + setup_command + ['--dist-dir', tmp_dist_dir] + config_settings["--global-option"]) - self.run_setup() + with no_install_setup_requires(): + self.run_setup() result_basename = _file_with_extension( tmp_dist_dir, result_extension) diff --git a/setuptools/tests/test_build_meta.py b/setuptools/tests/test_build_meta.py index 8fcf3055ff..fdb4b95010 100644 --- a/setuptools/tests/test_build_meta.py +++ b/setuptools/tests/test_build_meta.py @@ -380,7 +380,7 @@ def test_setup_requires(self, setup_literal, requirements, use_wheel, setup( name="qux", version="0.0.0", - py_modules=["hello.py"], + py_modules=["hello"], setup_requires={setup_literal}, ) """).format(setup_literal=setup_literal), @@ -407,6 +407,35 @@ def run(): assert expected == sorted(actual) + def test_dont_install_setup_requires(self, tmpdir_cwd): + files = { + 'setup.py': DALS(""" + from setuptools import setup + + setup( + name="qux", + version="0.0.0", + py_modules=["hello"], + setup_requires=["does-not-exist >99"], + ) + """), + 'hello.py': DALS(""" + def run(): + print('hello') + """), + } + + build_files(files) + + build_backend = self.get_build_backend() + + dist_dir = os.path.abspath('pip-dist-info') + os.makedirs(dist_dir) + + # does-not-exist can't be satisfied, so if it attempts to install + # setup_requires, it will fail. + build_backend.prepare_metadata_for_build_wheel(dist_dir) + _sys_argv_0_passthrough = { 'setup.py': DALS(""" import os