Add option to include build-system dependencies

Fixes jazzband#1396

piptools/scripts/compile.py

@@ -6,9 +6,11 @@
 import sys
 import tempfile
 from typing import IO, Any, BinaryIO, cast
+from typing import IO, Any, BinaryIO, List, Optional, Set, Tuple, Union, cast
 
 import click
-from build import BuildBackendException
+import pep517
+from build import BuildBackendException, ProjectBuilder
 from build.util import project_wheel_metadata
 from click.utils import LazyFile, safecall
 from pip._internal.commands import create_command
@@ -38,6 +40,14 @@
 METADATA_FILENAMES = frozenset({"setup.py", "setup.cfg", "pyproject.toml"})
 
 
+def _build_system_requires(src_dir: str) -> Set[str]:
+    result = ProjectBuilder(
+        src_dir, runner=pep517.quiet_subprocess_runner
+    ).build_system_requires
+    assert isinstance(result, set)
+    return result
+
+
 def _get_default_option(option_name: str) -> Any:
     """
     Get default value of the pip's option (including option from pip.conf)
@@ -291,6 +301,12 @@ def _determine_linesep(
     help="Specify a package to consider unsafe; may be used more than once. "
     f"Replaces default unsafe packages: {', '.join(sorted(UNSAFE_PACKAGES))}",
 )
+@click.option(
+    "--build-system-requires/--no-build-system-requires",
+    is_flag=True,
+    default=False,
+    help="Pin also build requirements",
+)
 def cli(
     ctx: click.Context,
     verbose: int,
@@ -328,6 +344,7 @@ def cli(
     emit_index_url: bool,
     emit_options: bool,
     unsafe_package: tuple[str, ...],
+    build_system_requires: bool,
 ) -> None:
     """
     Compiles requirements.txt from requirements.in, pyproject.toml, setup.cfg,
@@ -477,10 +494,8 @@ def cli(
         elif is_setup_file:
             setup_file_found = True
             try:
-                metadata = project_wheel_metadata(
-                    os.path.dirname(os.path.abspath(src_file)),
-                    isolated=build_isolation,
-                )
+                src_dir = os.path.dirname(os.path.abspath(src_file))
+                metadata = project_wheel_metadata(src_dir)
             except BuildBackendException as e:
                 log.error(str(e))
                 log.error(f"Failed to parse {os.path.abspath(src_file)}")
@@ -497,6 +512,13 @@ def cli(
                     msg = "--extra has no effect when used with --all-extras"
                     raise click.BadParameter(msg)
                 extras = tuple(metadata.get_all("Provides-Extra"))
+            if build_system_requires:
+                constraints.extend(
+                    [
+                        install_req_from_line(req, comes_from=comes_from)
+                        for req in _build_system_requires(src_dir)
+                    ]
+                )
         else:
             constraints.extend(
                 parse_requirements(

setup.cfg

@@ -35,6 +35,7 @@ install_requires =
     build
     click >= 8
     pip >= 22.2
+    pep517
     # indirect dependencies
     setuptools  # typically needed when pip-tools invokes setup.py
     wheel  # pip plugin needed by pip-tools