feat: allow specifying build constraints for dependencies

docs/pyproject.md

@@ -924,6 +924,28 @@ my-plugin = ">=1.0,<2.0"
 
 See [Project plugins]({{< relref "plugins#project-plugins" >}}) for more information.
 
+### build-constraints
+
+In this section, you can specify additional constraints to apply when creating the build
+environment for a dependency. This is useful if a package does not provide wheels
+(or shall be built from source for other reasons)
+and specifies too loose build requirements (without an upper bound)
+and is not compatible with current versions of one of its build requirements.
+
+For example, if your project depends on `some-package`, which only provides an sdist
+and defines its build requirements as `build-requires = ["setuptools"]`,
+but is incompatible with `setuptools >= 78`, building the package will probably fail
+because per default the latest setuptools will be chosen. In this case, you can
+work around this issue of `some-package` as follows:
+
+```toml
+[tool.poetry.build-constraints]
+some-package = { setuptools = "<78" }
+```
+
+The syntax for specifying constraints is the same as for specifying dependencies
+in the `tool.poetry` section.
+
 ## Poetry and PEP-517
 
 [PEP-517](https://www.python.org/dev/peps/pep-0517/) introduces a standard way

src/poetry/console/application.py

@@ -616,6 +616,7 @@ def configure_installer_for_command(command: InstallerCommand, io: IO) -> None:
             poetry.pool,
             poetry.config,
             disable_cache=poetry.disable_cache,
+            build_constraints=poetry.build_constraints,
         )
         command.set_installer(installer)
 

src/poetry/factory.py

@@ -9,6 +9,7 @@
 from typing import cast
 
 from cleo.io.null_io import NullIO
+from packaging.utils import NormalizedName
 from packaging.utils import canonicalize_name
 from poetry.core.constraints.version import Version
 from poetry.core.constraints.version import parse_constraint
@@ -24,13 +25,15 @@
 from poetry.plugins.plugin_manager import PluginManager
 from poetry.poetry import Poetry
 from poetry.toml.file import TOMLFile
+from poetry.utils.isolated_build import CONSTRAINTS_GROUP_NAME
 
 
 if TYPE_CHECKING:
     from collections.abc import Iterable
     from pathlib import Path
 
     from cleo.io.io import IO
+    from poetry.core.packages.dependency import Dependency
     from poetry.core.packages.package import Package
     from tomlkit.toml_document import TOMLDocument
 
@@ -68,6 +71,23 @@ def create_poetry(
                     f" but you are using Poetry {version}"
                 )
 
+        build_constraints: dict[NormalizedName, list[Dependency]] = {}
+        for name, constraints in base_poetry.local_config.get(
+            "build-constraints", {}
+        ).items():
+            name = canonicalize_name(name)
+            build_constraints[name] = []
+            for dep_name, constraint in constraints.items():
+                _constraints = (
+                    constraint if isinstance(constraint, list) else [constraint]
+                )
+                for _constraint in _constraints:
+                    build_constraints[name].append(
+                        Factory.create_dependency(
+                            dep_name, _constraint, groups=[CONSTRAINTS_GROUP_NAME]
+                        )
+                    )
+
         poetry_file = base_poetry.pyproject_path
         locker = Locker(poetry_file.parent / "poetry.lock", base_poetry.pyproject.data)
 
@@ -99,7 +119,8 @@ def create_poetry(
             base_poetry.package,
             locker,
             config,
-            disable_cache,
+            disable_cache=disable_cache,
+            build_constraints=build_constraints,
         )
 
         poetry.set_pool(

src/poetry/installation/chef.py

@@ -16,6 +16,7 @@
     from collections.abc import Sequence
 
     from build import DistributionType
+    from poetry.core.packages.dependency import Dependency
 
     from poetry.repositories import RepositoryPool
     from poetry.utils.cache import ArtifactCache
@@ -40,6 +41,7 @@ def prepare(
         *,
         editable: bool = False,
         config_settings: Mapping[str, str | Sequence[str]] | None = None,
+        build_constraints: list[Dependency] | None = None,
     ) -> Path:
         if not self._should_prepare(archive):
             return archive
@@ -51,10 +53,14 @@ def prepare(
                 destination=destination,
                 editable=editable,
                 config_settings=config_settings,
+                build_constraints=build_constraints,
             )
 
         return self._prepare_sdist(
-            archive, destination=output_dir, config_settings=config_settings
+            archive,
+            destination=output_dir,
+            config_settings=config_settings,
+            build_constraints=build_constraints,
         )
 
     def _prepare(
@@ -64,13 +70,15 @@ def _prepare(
         *,
         editable: bool = False,
         config_settings: Mapping[str, str | Sequence[str]] | None = None,
+        build_constraints: list[Dependency] | None = None,
     ) -> Path:
         distribution: DistributionType = "editable" if editable else "wheel"
         with isolated_builder(
             source=directory,
             distribution=distribution,
             python_executable=self._env.python,
             pool=self._pool,
+            build_constraints=build_constraints,
         ) as builder:
             return Path(
                 builder.build(
@@ -85,6 +93,7 @@ def _prepare_sdist(
         archive: Path,
         destination: Path | None = None,
         config_settings: Mapping[str, str | Sequence[str]] | None = None,
+        build_constraints: list[Dependency] | None = None,
     ) -> Path:
         from poetry.core.packages.utils.link import Link
 
@@ -115,6 +124,7 @@ def _prepare_sdist(
                 sdist_dir,
                 destination,
                 config_settings=config_settings,
+                build_constraints=build_constraints,
             )
 
     def _should_prepare(self, archive: Path) -> bool:

src/poetry/installation/executor.py

@@ -45,6 +45,7 @@
     from cleo.io.io import IO
     from cleo.io.outputs.section_output import SectionOutput
     from packaging.utils import NormalizedName
+    from poetry.core.packages.dependency import Dependency
     from poetry.core.packages.package import Package
 
     from poetry.config.config import Config
@@ -68,13 +69,16 @@ def __init__(
         io: IO,
         parallel: bool | None = None,
         disable_cache: bool = False,
+        *,
+        build_constraints: Mapping[NormalizedName, list[Dependency]] | None = None,
     ) -> None:
         self._env = env
         self._io = io
         self._dry_run = False
         self._enabled = True
         self._verbose = False
         self._wheel_installer = WheelInstaller(self._env)
+        self._build_constraints = build_constraints or {}
 
         if parallel is None:
             parallel = config.get("installer.parallel", True)
@@ -647,11 +651,13 @@ def _prepare_archive(
 
         self._populate_hashes_dict(archive, package)
 
+        name = operation.package.name
         return self._chef.prepare(
             archive,
             editable=package.develop,
             output_dir=output_dir,
-            config_settings=self._build_config_settings.get(operation.package.name),
+            config_settings=self._build_config_settings.get(name),
+            build_constraints=self._build_constraints.get(name),
         )
 
     def _prepare_git_archive(self, operation: Install | Update) -> Path:
@@ -761,10 +767,12 @@ def _download_link(self, operation: Install | Update, link: Link) -> Path:
             )
             self._write(operation, message)
 
+            name = operation.package.name
             archive = self._chef.prepare(
                 archive,
                 output_dir=original_archive.parent,
-                config_settings=self._build_config_settings.get(operation.package.name),
+                config_settings=self._build_config_settings.get(name),
+                build_constraints=self._build_constraints.get(name),
             )
 
         # Use the original archive to provide the correct hash.

src/poetry/installation/installer.py

@@ -16,9 +16,11 @@
 
 if TYPE_CHECKING:
     from collections.abc import Iterable
+    from collections.abc import Mapping
 
     from cleo.io.io import IO
     from packaging.utils import NormalizedName
+    from poetry.core.packages.dependency import Dependency
     from poetry.core.packages.package import Package
     from poetry.core.packages.path_dependency import PathDependency
     from poetry.core.packages.project_package import ProjectPackage
@@ -42,6 +44,8 @@ def __init__(
         installed: InstalledRepository | None = None,
         executor: Executor | None = None,
         disable_cache: bool = False,
+        *,
+        build_constraints: Mapping[NormalizedName, list[Dependency]] | None = None,
     ) -> None:
         self._io = io
         self._env = env
@@ -64,7 +68,12 @@ def __init__(
 
         if executor is None:
             executor = Executor(
-                self._env, self._pool, config, self._io, disable_cache=disable_cache
+                self._env,
+                self._pool,
+                config,
+                self._io,
+                disable_cache=disable_cache,
+                build_constraints=build_constraints,
             )
 
         self._executor = executor

src/poetry/json/schemas/poetry.json

@@ -24,6 +24,15 @@
       "items": {
         "$ref": "#/definitions/repository"
       }
+    },
+    "build-constraints": {
+      "type": "object",
+      "description": "This is a dict of package name (keys) and version constraints (values) to restrict build requirements for a package.",
+      "patternProperties": {
+        "^[a-zA-Z-_.0-9]+$": {
+          "$ref": "#/definitions/dependencies"
+        }
+      }
     }
   },
   "definitions": {

src/poetry/poetry.py

@@ -12,8 +12,11 @@
 
 
 if TYPE_CHECKING:
+    from collections.abc import Mapping
     from pathlib import Path
 
+    from packaging.utils import NormalizedName
+    from poetry.core.packages.dependency import Dependency
     from poetry.core.packages.project_package import ProjectPackage
 
     from poetry.config.config import Config
@@ -34,6 +37,8 @@ def __init__(
         locker: Locker,
         config: Config,
         disable_cache: bool = False,
+        *,
+        build_constraints: Mapping[NormalizedName, list[Dependency]] | None = None,
     ) -> None:
         from poetry.repositories.repository_pool import RepositoryPool
 
@@ -44,6 +49,7 @@ def __init__(
         self._pool = RepositoryPool(config=config)
         self._plugin_manager: PluginManager | None = None
         self._disable_cache = disable_cache
+        self._build_constraints = build_constraints or {}
 
     @property
     def pyproject(self) -> PyProjectTOML:
@@ -70,6 +76,10 @@ def config(self) -> Config:
     def disable_cache(self) -> bool:
         return self._disable_cache
 
+    @property
+    def build_constraints(self) -> Mapping[NormalizedName, list[Dependency]]:
+        return self._build_constraints
+
     def set_locker(self, locker: Locker) -> Poetry:
         self._locker = locker
 

src/poetry/utils/isolated_build.py

@@ -10,6 +10,7 @@
 
 from build import BuildBackendException
 from build.env import IsolatedEnv as BaseIsolatedEnv
+from poetry.core.packages.dependency_group import DependencyGroup
 
 from poetry.utils._compat import decode
 from poetry.utils.env import Env
@@ -24,10 +25,14 @@
 
     from build import DistributionType
     from build import ProjectBuilder
+    from poetry.core.packages.dependency import Dependency
 
     from poetry.repositories import RepositoryPool
 
 
+CONSTRAINTS_GROUP_NAME = "constraints"
+
+
 class IsolatedBuildBaseError(Exception): ...
 
 
@@ -111,7 +116,12 @@ def make_extra_environ(self) -> dict[str, str]:
             )
         }
 
-    def install(self, requirements: Collection[str]) -> None:
+    def install(
+        self,
+        requirements: Collection[str],
+        *,
+        constraints: list[Dependency] | None = None,
+    ) -> None:
         from cleo.io.buffered_io import BufferedIO
         from poetry.core.packages.dependency import Dependency
         from poetry.core.packages.project_package import ProjectPackage
@@ -136,6 +146,13 @@ def install(self, requirements: Collection[str]) -> None:
                 # safe as this environment is ephemeral
                 package.add_dependency(dependency)
 
+        if constraints:
+            constraints_group = DependencyGroup(CONSTRAINTS_GROUP_NAME, optional=True)
+            for constraint in constraints:
+                if constraint.marker.validate(env_markers):
+                    constraints_group.add_dependency(constraint)
+            package.add_dependency_group(constraints_group)
+
         io = BufferedIO()
 
         installer = Installer(
@@ -161,6 +178,8 @@ def isolated_builder(
     distribution: DistributionType = "wheel",
     python_executable: Path | None = None,
     pool: RepositoryPool | None = None,
+    *,
+    build_constraints: list[Dependency] | None = None,
 ) -> Iterator[ProjectBuilder]:
     from build import ProjectBuilder
     from pyproject_hooks import quiet_subprocess_runner
@@ -196,12 +215,15 @@ def isolated_builder(
             )
 
             with redirect_stdout(stdout):
-                env.install(builder.build_system_requires)
+                env.install(
+                    builder.build_system_requires, constraints=build_constraints
+                )
 
                 # we repeat the build system requirements to avoid poetry installer from removing them
                 env.install(
                     builder.build_system_requires
-                    | builder.get_requires_for_build(distribution)
+                    | builder.get_requires_for_build(distribution),
+                    constraints=build_constraints,
                 )
 
                 yield builder

tests/fixtures/build_constraints/pyproject.toml

@@ -0,0 +1,14 @@
+[project]
+name = "build-constraints"
+version = "0.1.0"
+
+[tool.poetry.build-constraints]
+Legacy-Lib = { setuptools = "<75" }
+no-constraints = {}
+
+[tool.poetry.build-constraints.c-ext-lib]
+Cython = { version = "<3.1", source = "pypi" }
+setuptools = [
+    { version = ">=60,<75", python = "<3.9" },
+    { version = ">=75", python = ">=3.8" }
+]