python_site_packages_path can be specified in the build section

conda_build/metadata.py

@@ -628,6 +628,7 @@ def parse(data, config, path=None):
         "error_overdepending": None,
         "error_overlinking": None,
         "overlinking_ignore_patterns": [],
+        "python_site_packages_path": str,
     },
     "outputs": {
         "name": None,
@@ -1800,6 +1801,8 @@ def info_index(self):
             d["provides_features"] = self.get_value("build/provides_features")
         if self.get_value("build/requires_features"):
             d["requires_features"] = self.get_value("build/requires_features")
+        if self.get_value("build/python_site_packages_path"):
+            d["python_site_packages_path"] = self.get_value("build/python_site_packages_path")
         if self.noarch:
             d["platform"] = d["arch"] = None
             d["subdir"] = "noarch"

docs/source/resources/define-metadata.rst

@@ -373,6 +373,19 @@ Python in macOS. The default is ``False``.
    build:
      osx_is_app: True
 
+python_site_packages_path
+-------------------------
+
+Packages with a name of ``python`` can optionally specify the location of the
+site-packages directory relative to the root of the environment with
+``python_site_packages_path``. This should only be used in ``python`` packages
+and only when the path is not the CPython default.
+
+.. code-block:: yaml
+
+   build:
+     python_site_packages_path: lib/python3.13t/site-packages
+
 
 Track features
 --------------

news/5502-python_site_packages_path-can-be-specified-in-the-build-section

@@ -0,0 +1,19 @@
+### Enhancements
+
+* The location of the site-packages directory can be specified in `python_site_packages_path` in the build section of a recipe (#5502).
+
+### Bug fixes
+
+* <news item>
+
+### Deprecations
+
+* <news item>
+
+### Docs
+
+* <news item>
+
+### Other
+
+* <news item>

tests/test-recipes/metadata/_python_site_packages_path/meta.yaml

@@ -0,0 +1,6 @@
+package:
+  name: python
+  version: 3.99.99
+
+build:
+  python_site_packages_path: "some/path"

tests/test_api_build.py

@@ -1705,6 +1705,15 @@ def test_provides_features_metadata(testing_config):
     assert index["provides_features"] == {"test2": "also_ok"}
 
 
+@pytest.mark.sanity
+def test_python_site_packages_path(testing_config):
+    recipe = os.path.join(metadata_dir, "_python_site_packages_path")
+    out = api.build(recipe, config=testing_config)[0]
+    index = json.loads(package_has_file(out, "info/index.json"))
+    assert "python_site_packages_path" in index
+    assert index["python_site_packages_path"] == "some/path"
+
+
 def test_overlinking_detection(
     testing_config, testing_workdir, variants_conda_build_sysroot
 ):