gh-138489: Install build-details.json on Windows

.github/workflows/mypy.yml

@@ -17,7 +17,7 @@ on:
       - "Tools/build/check_warnings.py"
       - "Tools/build/compute-changes.py"
       - "Tools/build/deepfreeze.py"
-      - "Tools/build/generate-build-details.py"
+      - "Tools/build/generate_build_details.py"
       - "Tools/build/generate_sbom.py"
       - "Tools/build/generate_stdlib_module_names.py"
       - "Tools/build/mypy.ini"

.gitignore

@@ -45,6 +45,8 @@ gmon.out
 .pytest_cache/
 .ruff_cache/
 .DS_Store
+__install__.json
+build-details.json
 
 *.exe
 

Lib/test/test_build_details.py

@@ -1,32 +1,18 @@
-import importlib
 import json
 import os
 import os.path
 import sys
 import sysconfig
 import string
 import unittest
-from pathlib import Path
 
 from test.support import is_android, is_apple_mobile, is_wasm32
-
-BASE_PATH = Path(
-    __file__,  # Lib/test/test_build_details.py
-    '..',  # Lib/test
-    '..',  # Lib
-    '..',  # <src/install dir>
-).resolve()
-MODULE_PATH = BASE_PATH / 'Tools' / 'build' / 'generate-build-details.py'
+from test.test_tools import imports_under_tool
 
 try:
-    # Import "generate-build-details.py" as "generate_build_details"
-    spec = importlib.util.spec_from_file_location(
-        "generate_build_details", MODULE_PATH
-    )
-    generate_build_details = importlib.util.module_from_spec(spec)
-    sys.modules["generate_build_details"] = generate_build_details
-    spec.loader.exec_module(generate_build_details)
-except (FileNotFoundError, ImportError):
+    with imports_under_tool('build'):
+        import generate_build_details
+except ImportError:
     generate_build_details = None
 
 
@@ -116,18 +102,20 @@ def test_implementation(self):
 )
 
 
-@unittest.skipIf(os.name != 'posix', 'Feature only implemented on POSIX right now')
 @unittest.skipIf(is_wasm32, 'Feature not available on WebAssembly builds')
 class CPythonBuildDetailsTests(unittest.TestCase, FormatTestsBase):
     """Test CPython's install details file implementation."""
 
     @property
     def location(self):
         if sysconfig.is_python_build():
-            projectdir = sysconfig.get_config_var('projectbase')
-            pybuilddir = os.path.join(projectdir, 'pybuilddir.txt')
-            with open(pybuilddir, encoding='utf-8') as f:
-                dirname = os.path.join(projectdir, f.read())
+            if sys.platform == 'win32':
+                dirname = sysconfig.get_config_var('BINDIR')
+            else:
+                projectdir = sysconfig.get_config_var('projectbase')
+                pybuilddir = os.path.join(projectdir, 'pybuilddir.txt')
+                with open(pybuilddir, encoding='utf-8') as f:
+                    dirname = os.path.join(projectdir, f.read())
         else:
             dirname = sysconfig.get_path('stdlib')
         return os.path.join(dirname, 'build-details.json')
@@ -176,9 +164,8 @@ def test_c_api(self):
 
 @unittest.skipIf(
     generate_build_details is None,
-    "Failed to import generate-build-details"
+    "Failed to import generate_build_details",
 )
-@unittest.skipIf(os.name != 'posix', 'Feature only implemented on POSIX right now')
 @unittest.skipIf(is_wasm32, 'Feature not available on WebAssembly builds')
 class BuildDetailsRelativePathsTests(unittest.TestCase):
     @property
@@ -189,7 +176,7 @@ def build_details_absolute_paths(self):
     @property
     def build_details_relative_paths(self):
         data = self.build_details_absolute_paths
-        generate_build_details.make_paths_relative(data, config_path=None)
+        generate_build_details.make_paths_relative(data, base_path=None)
         return data
 
     def test_round_trip(self):

Makefile.pre.in

@@ -1004,7 +1004,7 @@ pybuilddir.txt: $(PYTHON_FOR_BUILD_DEPS)
 	fi
 
 build-details.json: pybuilddir.txt
-	$(RUNSHARED) $(PYTHON_FOR_BUILD) $(srcdir)/Tools/build/generate-build-details.py `cat pybuilddir.txt`/build-details.json
+	$(RUNSHARED) $(PYTHON_FOR_BUILD) $(srcdir)/Tools/build/generate_build_details.py `cat pybuilddir.txt`/build-details.json
 
 # Build static library
 $(LIBRARY): $(LIBRARY_OBJS)

Misc/NEWS.d/next/Core_and_Builtins/2025-09-04-00-32-28.gh-issue-138489.Adc9Lx.rst

@@ -0,0 +1,3 @@
+The :pep:`739` :file:`build-details.json` file is now generated and
+installed on Windows.
+Patch by Adam Turner.

PC/layout/main.py

@@ -22,6 +22,7 @@
     __path__ = [str(Path(__file__).resolve().parent)]
 
 from .support.appxmanifest import *
+from .support.build_details import *
 from .support.catalog import *
 from .support.constants import *
 from .support.filesets import *
@@ -319,6 +320,9 @@ def _c(d):
     if ns.include_install_json or ns.include_install_embed_json or ns.include_install_test_json:
         yield "__install__.json", ns.temp / "__install__.json"
 
+    if ns.include_build_details_json:
+        yield "build-details.json", ns.temp / "build-details.json"
+
 
 def _compile_one_py(src, dest, name, optimize, checked=True):
     import py_compile
@@ -426,6 +430,12 @@ def generate_source_files(ns):
         with open(ns.temp / "__install__.json", "w", encoding="utf-8") as f:
             json.dump(calculate_install_json(ns, for_test=True), f, indent=2)
 
+    if ns.include_build_details_json:
+        log_info("Generating build-details.json in {}", ns.temp)
+        ns.temp.mkdir(parents=True, exist_ok=True)
+        base_path = Path(sys.base_prefix, "build-details.json")
+        write_relative_build_details(ns.temp / "build-details.json", base_path)
+
 
 def _create_zip_file(ns):
     if not ns.zip:

PC/layout/support/build_details.py

@@ -0,0 +1,37 @@
+"""
+Generate the PEP 739 'build-details.json' document.
+"""
+
+import sys
+from pathlib import Path
+
+PEP739_SCHEMA_VERSION = '1.0'
+
+ROOT_DIR = Path(
+    __file__,  # PC/layout/support/build_details.py
+    '..',  # PC/layout/support
+    '..',  # PC/layout
+    '..',  # PC
+    '..',  # <src/install dir>
+).resolve()
+TOOLS_BUILD_DIR = ROOT_DIR / 'Tools' / 'build'
+
+sys_path = sys.path[:]
+try:
+    sys.path.insert(0, str(TOOLS_BUILD_DIR))
+    import generate_build_details
+except ImportError:
+    generate_build_details = None
+finally:
+    sys.path = sys_path
+    del sys_path
+
+
+def write_relative_build_details(out_path, base_path):
+    if generate_build_details is None:
+        return
+    generate_build_details.write_build_details(
+        schema_version=PEP739_SCHEMA_VERSION,
+        base_path=base_path,
+        location=out_path,
+    )

PC/layout/support/options.py

@@ -39,6 +39,7 @@ def public(f):
     "install-json": {"help": "a PyManager __install__.json file"},
     "install-embed-json": {"help": "a PyManager __install__.json file for embeddable distro"},
     "install-test-json": {"help": "a PyManager __install__.json for the test distro"},
+    "build-details-json": {"help": "a PEP 739 build-details.json file"},
 }
 
 
@@ -56,6 +57,7 @@ def public(f):
             "appxmanifest",
             "alias",
             "alias3x",
+            "build-details-json",
             # XXX: Disabled for now "precompile",
         ],
     },
@@ -69,9 +71,10 @@ def public(f):
             "props",
             "nuspec",
             "alias",
+            "build-details-json",
         ],
     },
-    "iot": {"help": "Windows IoT Core", "options": ["alias", "stable", "pip"]},
+    "iot": {"help": "Windows IoT Core", "options": ["alias", "stable", "pip", "build-details-json"]},
     "default": {
         "help": "development kit package",
         "options": [
@@ -85,6 +88,7 @@ def public(f):
             "symbols",
             "html-doc",
             "alias",
+            "build-details-json",
         ],
     },
     "embed": {
@@ -96,6 +100,7 @@ def public(f):
             "flat-dlls",
             "underpth",
             "precompile",
+            "build-details-json",
         ],
     },
     "pymanager": {
@@ -109,6 +114,7 @@ def public(f):
             "dev",
             "html-doc",
             "install-json",
+            "build-details-json",
         ],
     },
     "pymanager-test": {
@@ -124,6 +130,7 @@ def public(f):
             "symbols",
             "tests",
             "install-test-json",
+            "build-details-json",
         ],
     },
 }

PCbuild/python.vcxproj

@@ -126,6 +126,12 @@
     <Message Text="Generating $(OutDir)pybuilddir.txt" />
     <WriteLinesToFile File="$(OutDir)pybuilddir.txt" Lines="%0D%0A" Overwrite="true" />
   </Target>
+  <Target Name="GenerateBuildDetailsJSON" AfterTargets="Link">
+    <Message Text="Generating $(OutDir)build-details.json" />
+    <Exec Command='setlocal
+set PYTHONPATH=$(PySourcePath)Lib
+"$(OutDir)$(PyExeName)$(PyDebugExt).exe" "$(PySourcePath)Tools\build\generate_build_details.py" "$(OutDir)build-details.json"' ContinueOnError="true" />
+  </Target>
   <Target Name="ValidateUcrtbase" AfterTargets="AfterBuild" Condition="$(Configuration) != 'PGInstrument' and $(Platform) != 'ARM' and $(Platform) != 'ARM64'">
     <PropertyGroup>
       <UcrtName>ucrtbase</UcrtName>

PCbuild/pythoncore.vcxproj

@@ -735,4 +735,7 @@
   <Target Name="_DeletePyBuildDirTxt" BeforeTargets="PrepareForBuild">
     <Delete Files="$(OutDir)pybuilddir.txt" />
   </Target>
+  <Target Name="_DeleteBuildDetailsJson" BeforeTargets="PrepareForBuild">
+    <Delete Files="$(OutDir)build-details.json" />
+  </Target>
 </Project>