Rename constraints param of DefaultIsolatedEnv.install

This is a vestige from a previous version where the constraints.txt
file was incorrectly interpreted as a requirement list.

Author: layday

docs/changelog/1160.removal.rst

@@ -0,0 +1,2 @@
+Remove ``constraints`` parameter of ``env.DefaultIsolatedEnv.install`` and replace with ``constraints_txt_path``. - by
+:user:`layday`

src/build/__main__.py

@@ -218,17 +218,7 @@ def _bootstrap_build_env(
         with DefaultIsolatedEnv(installer=installer, path=env_dir) as env:
             builder = ProjectBuilder.from_isolated_env(env, srcdir, runner=runner)
 
-            install = env.install
-            if dependency_constraints_txt:
-                with open(dependency_constraints_txt, encoding='utf-8') as dependency_constraints_file:
-                    constraints_text = dependency_constraints_file.read()
-                if constraints_text.strip():
-                    # Passed through as a single element instead of re-parsed into lines, so a requirement can never
-                    # be split from its `--hash` continuation lines (as produced by `pip-compile --generate-hashes`)
-                    # and silently lose its hash check. env.py's installer backends reconstruct the original file via
-                    # `'\n'.join(constraints)` (see `_PipInstaller`/`_UvInstaller.install_dependencies`), a no-op here
-                    # since there is only one element.
-                    install = partial(install, constraints=(constraints_text,))
+            install = partial(env.install, constraints_txt_path=dependency_constraints_txt)
 
             # first install the build dependencies
             install(builder.build_system_requires, _fresh=True)

src/build/env.py

@@ -59,6 +59,8 @@
     else:
         from typing import Self
 
+    from . import _types
+
     class _DistArgs(typing.TypedDict, total=False):
         path: list[str]
 
@@ -211,7 +213,7 @@ def installed_versions(self, requirements: Collection[str]) -> dict[str, str]:
     def install(
         self,
         requirements: Collection[str],
-        constraints: Collection[str] = (),
+        constraints_txt_path: _types.StrPath | None = None,
         *,
         _fresh: bool = False,  # Used internally by CLI to support preset PYTHONPATH
     ) -> None:
@@ -230,7 +232,7 @@ def install(
             'Installing packages in isolated environment:\n' + '\n'.join(f'- {r}' for r in sorted(requirements)),
             kind=('step',),
         )
-        self._env_backend.install_dependencies(requirements, constraints, _fresh=_fresh)
+        self._env_backend.install_dependencies(requirements, constraints_txt_path, _fresh=_fresh)
 
 
 def _canonical_requirement_name(requirement: str) -> str | None:
@@ -250,7 +252,7 @@ def create(self, path: str) -> None: ...
     def install_dependencies(
         self,
         requirements: Collection[str],
-        constraints: Collection[str],
+        constraints_txt_path: _types.StrPath | None,
         *,
         _fresh: bool = False,
     ) -> None: ...
@@ -395,7 +397,7 @@ def create(self, path: str) -> None:
     def install_dependencies(
         self,
         requirements: Collection[str],
-        constraints: Collection[str],
+        constraints_txt_path: _types.StrPath | None,
         *,
         _fresh: bool = False,
     ) -> None:
@@ -423,14 +425,8 @@ def install_dependencies(
 
             cmd += ['-r', os.path.abspath(requirement_file.name)]
 
-            if constraints:
-                with tempfile.NamedTemporaryFile(
-                    'w', prefix='build-constraints-', suffix='.txt', delete=False, encoding='utf-8'
-                ) as constraint_file:
-                    constraint_file.write('\n'.join(constraints))
-                exit_stack.callback(functools.partial(os.unlink, constraint_file.name))
-
-                cmd += ['-c', os.path.abspath(constraint_file.name)]
+            if constraints_txt_path:
+                cmd += ['-c', str(constraints_txt_path)]
 
             run_subprocess(cmd, env=_pip_env())
 
@@ -464,32 +460,25 @@ def create(self, path: str) -> None:
     def install_dependencies(  # pragma: no cover -- uv tests are skipped on PyPy, covered on CPython
         self,
         requirements: Collection[str],
-        constraints: Collection[str],
+        constraints_txt_path: _types.StrPath | None,
         *,
         _fresh: bool = False,
     ) -> None:
-        with contextlib.ExitStack() as exit_stack:
-            cmd = [self._uv_bin, 'pip']
-
-            if (verbosity := _ctx.verbosity) > 1:
-                cmd += [f'-{"v" * min(2, verbosity - 1)}']
+        cmd = [self._uv_bin, 'pip']
 
-            cmd += ['install', *requirements, '--python', self.python_executable]
+        if (verbosity := _ctx.verbosity) > 1:
+            cmd += [f'-{"v" * min(2, verbosity - 1)}']
 
-            if constraints:
-                with tempfile.NamedTemporaryFile(
-                    'w', prefix='build-constraints-', suffix='.txt', delete=False, encoding='utf-8'
-                ) as constraint_file:
-                    constraint_file.write('\n'.join(constraints))
-                exit_stack.callback(functools.partial(os.unlink, constraint_file.name))
+        cmd += ['install', *requirements, '--python', self.python_executable]
 
-                cmd += ['-c', os.path.abspath(constraint_file.name)]
+        if constraints_txt_path:
+            cmd += ['-c', str(constraints_txt_path)]
 
-            env = {k: v for k, v in os.environ.items() if k != 'PYTHONPATH'}
-            env['VIRTUAL_ENV'] = self._env_path
-            if 'UV_KEYRING_PROVIDER' not in os.environ and _has_keyring_cli():
-                env['UV_KEYRING_PROVIDER'] = 'subprocess'
-            run_subprocess(cmd, env=env)
+        env = {k: v for k, v in os.environ.items() if k != 'PYTHONPATH'}
+        env['VIRTUAL_ENV'] = self._env_path
+        if 'UV_KEYRING_PROVIDER' not in os.environ and _has_keyring_cli():
+            env['UV_KEYRING_PROVIDER'] = 'subprocess'
+        run_subprocess(cmd, env=env)
 
     @property
     def display_name(self) -> str:

tests/test_env.py

@@ -286,21 +286,27 @@ def test_install_short_circuits(
 
 
 @pytest.mark.parametrize('verbosity', range(3))
-@pytest.mark.parametrize('constraints', [[], ['foo']])
+@pytest.mark.parametrize('constraints_txt', ['', 'foo'])
 @pytest.mark.parametrize('fresh', [False, True])
 @pytest.mark.usefixtures('local_pip')
 def test_default_impl_install_cmd_well_formed(
+    tmp_path: Path,
     mocker: pytest_mock.MockerFixture,
     verbosity: int,
-    constraints: list[str],
+    constraints_txt: str,
     fresh: bool,
 ) -> None:
     mocker.patch.object(_ctx, 'verbosity', verbosity)
 
+    constraints_txt_path = None
+    if constraints_txt:
+        constraints_txt_path = tmp_path.joinpath('constraints.txt')
+        constraints_txt_path.write_text(constraints_txt, encoding='utf-8')
+
     with build.env.DefaultIsolatedEnv() as env:
         run_subprocess = mocker.patch('build.env.run_subprocess')
 
-        env.install(['some', 'requirements'], constraints, _fresh=fresh)
+        env.install(['some', 'requirements'], constraints_txt_path, _fresh=fresh)
 
         run_subprocess.assert_called_once_with(
             [
@@ -316,29 +322,35 @@ def test_default_impl_install_cmd_well_formed(
                 '--no-input',
                 '-r',
                 mocker.ANY,
-                *(['-c', mocker.ANY] if constraints else []),
+                *(['-c', str(constraints_txt_path)] if constraints_txt_path else []),
             ],
             env=mocker.ANY,
         )
 
 
 @pytest.mark.parametrize('verbosity', range(3))
-@pytest.mark.parametrize('constraints', [[], ['foo']])
+@pytest.mark.parametrize('constraints_txt', ['', 'foo'])
 @pytest.mark.parametrize('fresh', [False, True])
 @pytest.mark.skipif(IS_PYPY, reason='uv cannot find PyPy executable')
 @pytest.mark.skipif(MISSING_UV, reason='uv executable not found')
 def test_uv_impl_install_cmd_well_formed(  # pragma: no cover -- uv tests are skipped on PyPy, covered on CPython
+    tmp_path: Path,
     mocker: pytest_mock.MockerFixture,
     verbosity: int,
-    constraints: list[str],
+    constraints_txt: str,
     fresh: bool,
 ) -> None:
     mocker.patch.object(_ctx, 'verbosity', verbosity)
 
+    constraints_txt_path = None
+    if constraints_txt:
+        constraints_txt_path = tmp_path.joinpath('constraints.txt')
+        constraints_txt_path.write_text(constraints_txt, encoding='utf-8')
+
     with build.env.DefaultIsolatedEnv(installer='uv') as env:
         run_subprocess = mocker.patch('build.env.run_subprocess')
 
-        env.install(['some', 'requirements'], constraints, _fresh=fresh)
+        env.install(['some', 'requirements'], constraints_txt_path, _fresh=fresh)
 
         run_subprocess.assert_called_once_with(
             [
@@ -350,7 +362,7 @@ def test_uv_impl_install_cmd_well_formed(  # pragma: no cover -- uv tests are sk
                 'requirements',
                 '--python',
                 mocker.ANY,
-                *(['-c', mocker.ANY] if constraints else []),
+                *(['-c', str(constraints_txt_path)] if constraints_txt_path else []),
             ],
             env=mocker.ANY,
         )
@@ -360,7 +372,7 @@ def test_uv_impl_install_cmd_well_formed(  # pragma: no cover -- uv tests are sk
 
 @pytest.mark.usefixtures('local_pip')
 def test_default_impl_install_files_line_endings_not_doubled(mocker: pytest_mock.MockerFixture) -> None:
-    # The requirements/constraints files are opened in text mode, which translates every
+    # The requirements files are opened in text mode, which translates every
     # '\n' written to os.linesep -- '\r\n' on disk is correct on Windows. Joining with
     # os.linesep first (instead of '\n') would double-translate there, turning '\r\n' into
     # '\r\r\n'. Read back as bytes, before the files are deleted by the
@@ -372,38 +384,13 @@ def fake_run_subprocess(cmd: list[str], **_kwargs: object) -> None:
         for arg in args:
             if arg == '-r':
                 written['requirements'] = Path(next(args)).read_bytes()
-            elif arg == '-c':
-                written['constraints'] = Path(next(args)).read_bytes()
 
     with build.env.DefaultIsolatedEnv() as env:
         mocker.patch('build.env.run_subprocess', side_effect=fake_run_subprocess)
-        env.install(['some', 'requirements'], ['a-constraint', 'b-constraint'])
+        env.install(['some', 'requirements'])
 
     assert b'\r\r' not in written['requirements']
     assert written['requirements'].splitlines() == [b'some', b'requirements']
-    assert b'\r\r' not in written['constraints']
-    assert written['constraints'].splitlines() == [b'a-constraint', b'b-constraint']
-
-
-@pytest.mark.skipif(IS_PYPY, reason='uv cannot find PyPy executable')
-@pytest.mark.skipif(MISSING_UV, reason='uv executable not found')
-def test_uv_impl_install_files_line_endings_not_doubled(  # pragma: no cover -- skipped on PyPy, covered on CPython
-    mocker: pytest_mock.MockerFixture,
-) -> None:
-    written: dict[str, bytes] = {}
-
-    def fake_run_subprocess(cmd: list[str], **_kwargs: object) -> None:
-        args = iter(cmd)
-        for arg in args:
-            if arg == '-c':
-                written['constraints'] = Path(next(args)).read_bytes()
-
-    with build.env.DefaultIsolatedEnv(installer='uv') as env:
-        mocker.patch('build.env.run_subprocess', side_effect=fake_run_subprocess)
-        env.install(['some', 'requirements'], ['a-constraint', 'b-constraint'])
-
-    assert b'\r\r' not in written['constraints']
-    assert written['constraints'].splitlines() == [b'a-constraint', b'b-constraint']
 
 
 @pytest.mark.usefixtures('local_pip')

tests/test_main.py

@@ -219,10 +219,10 @@ def test_build_isolated(mocker: pytest_mock.MockerFixture, package_test_flit: st
 
     build.__main__.build_package(package_test_flit, '.', ['sdist'])
 
-    install.assert_any_call({'flit_core >=2,<4'}, _fresh=True)
+    install.assert_any_call({'flit_core >=2,<4'}, constraints_txt_path=None, _fresh=True)
 
     required_cmd.assert_called_with('sdist', None)
-    install.assert_any_call({'dep1', 'dep2'})
+    install.assert_any_call({'dep1', 'dep2'}, constraints_txt_path=None)
 
     build_cmd.assert_called_with('sdist', '.', None)
 
@@ -455,44 +455,7 @@ def test_build_package_with_constraints(
     with pytest.raises(build.BuildBackendException, match=re.escape("Backend 'flit_core.buildapi' is not available.")):
         build.__main__.build_package(package_test_flit, tmp_path, ['wheel'], dependency_constraints_txt=constraints_txt_path)
 
-    install.assert_any_call({'flit_core >=2,<4'}, constraints=('flit-core==12.34\nfoo==wot\n',), _fresh=True)
-
-
-@pytest.mark.isolated
-def test_build_package_with_constraints_passes_file_through_unmodified(
-    mocker: pytest_mock.MockerFixture, tmp_path: pathlib.Path, package_test_flit: str
-) -> None:
-    # As produced by e.g. `pip-compile --generate-hashes`: a requirement and its --hash options wrapped onto
-    # continuation lines. Regression test for the requirement/hash pair being split apart when re-parsed into
-    # individual lines - the file content must reach the installer byte-for-byte instead.
-    install = mocker.patch('build.env.DefaultIsolatedEnv.install')
-
-    constraints_text = (
-        'flit-core==12.34 \\\n    --hash=sha256:aaaa \\\n    --hash=sha256:bbbb\n    # via test\nfoo==wot \\\n'
-        '    --hash=sha256:cccc\n'
-    )
-    constraints_txt_path = tmp_path.joinpath('constraints.txt')
-    constraints_txt_path.write_text(constraints_text, encoding='utf-8')
-
-    with pytest.raises(build.BuildBackendException, match=re.escape("Backend 'flit_core.buildapi' is not available.")):
-        build.__main__.build_package(package_test_flit, tmp_path, ['wheel'], dependency_constraints_txt=constraints_txt_path)
-
-    install.assert_any_call({'flit_core >=2,<4'}, constraints=(constraints_text,), _fresh=True)
-
-
-@pytest.mark.isolated
-def test_build_package_with_empty_constraints_txt(
-    mocker: pytest_mock.MockerFixture, tmp_path: pathlib.Path, package_test_flit: str
-) -> None:
-    install = mocker.patch('build.env.DefaultIsolatedEnv.install')
-
-    constraints_txt_path = tmp_path.joinpath('constraints.txt')
-    constraints_txt_path.write_text('  \n\n', encoding='utf-8')
-
-    with pytest.raises(build.BuildBackendException, match=re.escape("Backend 'flit_core.buildapi' is not available.")):
-        build.__main__.build_package(package_test_flit, tmp_path, ['wheel'], dependency_constraints_txt=constraints_txt_path)
-
-    install.assert_any_call({'flit_core >=2,<4'}, _fresh=True)
+    install.assert_any_call({'flit_core >=2,<4'}, constraints_txt_path=constraints_txt_path, _fresh=True)
 
 
 @pytest.mark.pypy3323bug
@@ -954,8 +917,8 @@ def test_bootstrap_build_env_logs_versions(mocker: pytest_mock.MockerFixture) ->
     ) as result:
         assert result is builder
 
-    env.install.assert_any_call({'setuptools'}, _fresh=True)
-    env.install.assert_any_call({'wheel'})
+    env.install.assert_any_call({'setuptools'}, constraints_txt_path=None, _fresh=True)
+    env.install.assert_any_call({'wheel'}, constraints_txt_path=None)
     log_versions.assert_called_once_with(env, {'setuptools', 'wheel'})