fix(env): isolated env must validate requirements

This change ensures that when an isolated environment is created, the
temporary lockfile created does not consider dependencies that are not
valid for the environment. This reduces the possibility of constraint
errors when building dependencies from source that use complex
build-system requirements.

Resolves: #8409

Author: abn

src/poetry/utils/isolated_build.py

@@ -124,10 +124,17 @@ def install(self, requirements: Collection[str]) -> None:
         # We build Poetry dependencies from the requirements
         package = ProjectPackage("__root__", "0.0.0")
         package.python_versions = ".".join(str(v) for v in self._env.version_info[:3])
+        env_markers = self._env.get_marker_env()
 
         for requirement in requirements:
             dependency = Dependency.create_from_pep_508(requirement)
-            package.add_dependency(dependency)
+
+            if dependency.marker.is_empty() or dependency.marker.validate(env_markers):
+                # we ignore dependencies that are not valid for this environment
+                # this ensures that we do not end up with unnecessary constraint
+                # errors when solving build system requirements; this is assumed
+                # safe as this environment is ephemeral
+                package.add_dependency(dependency)
 
         io = BufferedIO()
 

tests/inspection/test_info.py

@@ -329,7 +329,8 @@ def test_info_no_setup_pkg_info_no_deps_dynamic(fixture_dir: FixtureDirGetter) -
 def test_info_setup_simple(mocker: MockerFixture, demo_setup: Path) -> None:
     spy = mocker.spy(VirtualEnv, "run")
     info = PackageInfo.from_directory(demo_setup)
-    assert spy.call_count == 4
+
+    assert spy.call_count == 6
     demo_check_info(info, requires_dist={"package"})
 
 

tests/utils/test_isolated_build.py

@@ -2,6 +2,7 @@
 
 import shutil
 import sys
+import uuid
 
 from pathlib import Path
 from typing import TYPE_CHECKING
@@ -56,6 +57,38 @@ def test_isolated_env_install_success(pool: RepositoryPool) -> None:
         )
 
 
+def test_isolated_env_install_discards_requirements_not_needed_by_env(
+    pool: RepositoryPool,
+) -> None:
+    with ephemeral_environment(Path(sys.executable)) as venv:
+        env = IsolatedEnv(venv, pool)
+        assert not InstalledRepository.load(venv).find_packages(
+            get_dependency("poetry-core")
+        )
+
+        venv_python_version = venv.get_marker_env().get("python_version")
+        package_one = uuid.uuid4().hex
+        package_two = uuid.uuid4().hex
+
+        env.install(
+            {
+                f"poetry-core; python_version=='{venv_python_version}'",
+                f"{package_one}>=1.0.0; python_version=='0.0'",
+                f"{package_two}>=2.0.0; platform_system=='Mirrors'",
+            }
+        )
+        assert InstalledRepository.load(venv).find_packages(
+            get_dependency("poetry-core")
+        )
+        assert not InstalledRepository.load(venv).find_packages(
+            get_dependency(package_one)
+        )
+
+        assert not InstalledRepository.load(venv).find_packages(
+            get_dependency(package_two)
+        )
+
+
 @pytest.mark.parametrize(
     ("requirements", "exception"),
     [