fix: use the python micro version to parse whl metadata in bzlmod

Add `<micro>` version to the target platform. Instead of `cpxy_os_cpu`
the target platform string format becomes `cpxy.z_os_cpu`. This is a
temporary measure until we get a better API for defining target
platforms.

Summary:
- [x] test `select_whls` function needs to be tested to ensure that the
  whl selection is not impacted when we have the full version in the
  target platform.
- [ ] `download_only` legacy whl code path in `bzlmod` needs further
  testing.
- [x] test `whl_config_setting` handling and config setting creation.
  The config settings in the hub repo should not use the full version,
  because from the outside, the whl is compatible with all `micro`
  versions of a given `3.<minor_version>` of the Python interpreter.
  This means that the already documented config setting do not need to
  be changed.
- [x] changelog.
- [x] `pep508_deps` tests for handling the `full_python_version`
  correctly.

Fixes #2319

Author: aignas

CHANGELOG.md

@@ -69,6 +69,9 @@ END_UNRELEASED_TEMPLATE
   * The `sys._base_executable` value will reflect the underlying interpreter,
     not venv interpreter.
   * The {obj}`//python/runtime_env_toolchains:all` toolchain now works with it.
+* (pypi) Correctly handle `METADATA` entries when `python_full_version` is used in
+  the environment marker.
+  Fixes [#2319](https://github.com/bazel-contrib/rules_python/issues/2319).
 
 {#v0-0-0-added}
 ### Added

python/private/pypi/BUILD.bazel

@@ -103,6 +103,7 @@ bzl_library(
         "//python/private:version_label_bzl",
         "@bazel_features//:features",
         "@pythons_hub//:interpreters_bzl",
+        "@pythons_hub//:versions_bzl",
     ],
 )
 

python/private/pypi/config_settings.bzl

@@ -42,6 +42,8 @@ specialized is as follows:
 * `:is_cp3<minor_version>_abi3_<platform_suffix>`
 * `:is_cp3<minor_version>_cp3<minor_version>_<platform_suffix>` and `:is_cp3<minor_version>_cp3<minor_version>t_<platform_suffix>`
 
+Optionally instead of `<minor_version>` there sometimes may be `<minor_version>.<micro_version>` used in order to fully specify the versions
+
 The specialization of free-threaded vs non-free-threaded wheels is the same as
 they are just variants of each other. The same goes for the specialization of
 `musllinux` vs `manylinux`.

python/private/pypi/extension.bzl

@@ -16,7 +16,9 @@
 
 load("@bazel_features//:features.bzl", "bazel_features")
 load("@pythons_hub//:interpreters.bzl", "INTERPRETER_LABELS")
+load("@pythons_hub//:versions.bzl", "MINOR_MAPPING")
 load("//python/private:auth.bzl", "AUTH_ATTRS")
+load("//python/private:full_version.bzl", "full_version")
 load("//python/private:normalize_name.bzl", "normalize_name")
 load("//python/private:repo_utils.bzl", "repo_utils")
 load("//python/private:semver.bzl", "semver")
@@ -68,6 +70,7 @@ def _create_whl_repos(
         pip_attr,
         whl_overrides,
         available_interpreters = INTERPRETER_LABELS,
+        minor_mapping = MINOR_MAPPING,
         get_index_urls = None):
     """create all of the whl repositories
 
@@ -159,8 +162,10 @@ def _create_whl_repos(
             requirements_osx = pip_attr.requirements_darwin,
             requirements_windows = pip_attr.requirements_windows,
             extra_pip_args = pip_attr.extra_pip_args,
-            # TODO @aignas 2025-04-15: pass the full version into here
-            python_version = major_minor,
+            python_version = full_version(
+                version = pip_attr.python_version,
+                minor_mapping = minor_mapping,
+            ),
             logger = logger,
         ),
         extra_pip_args = pip_attr.extra_pip_args,
@@ -304,9 +309,6 @@ def _whl_repos(*, requirement, whl_library_args, download_only, netrc, auth_patt
     if requirement.extra_pip_args:
         args["extra_pip_args"] = requirement.extra_pip_args
 
-    if download_only:
-        args.setdefault("experimental_target_platforms", requirement.target_platforms)
-
     target_platforms = requirement.target_platforms if multiple_requirements_for_whl else []
     repo_name = pypi_repo_name(
         normalize_name(requirement.distribution),

python/private/pypi/pkg_aliases.bzl

@@ -371,6 +371,9 @@ def get_filename_config_settings(
 
         abi = parsed.abi_tag
 
+        # TODO @aignas 2025-04-20: test
+        abi, _, _ = abi.partition(".")
+
         if parsed.platform_tag == "any":
             prefixes = ["{}{}_any".format(py, abi)]
         else:

python/private/pypi/render_pkg_aliases.bzl

@@ -143,6 +143,18 @@ def render_pkg_aliases(*, aliases, requirement_cycles = None, extra_hub_aliases
         files["_groups/BUILD.bazel"] = generate_group_library_build_bazel("", requirement_cycles)
     return files
 
+def _major_minor(python_version):
+    major, _, tail = python_version.partition(".")
+    minor, _, _ = tail.partition(".")
+    return "{}.{}".format(major, minor)
+
+def _major_minor_versions(python_versions):
+    if not python_versions:
+        return []
+
+    # Use a dict as a simple set
+    return sorted({_major_minor(v): None for v in python_versions})
+
 def render_multiplatform_pkg_aliases(*, aliases, **kwargs):
     """Render the multi-platform pkg aliases.
 
@@ -174,7 +186,7 @@ def render_multiplatform_pkg_aliases(*, aliases, **kwargs):
         glibc_versions = flag_versions.get("glibc_versions", []),
         muslc_versions = flag_versions.get("muslc_versions", []),
         osx_versions = flag_versions.get("osx_versions", []),
-        python_versions = flag_versions.get("python_versions", []),
+        python_versions = _major_minor_versions(flag_versions.get("python_versions", [])),
         target_platforms = flag_versions.get("target_platforms", []),
         visibility = ["//:__subpackages__"],
     )

python/private/pypi/requirements_files_by_platform.bzl

@@ -91,13 +91,12 @@ def _platforms_from_args(extra_pip_args):
     return list(platforms.keys())
 
 def _platform(platform_string, python_version = None):
-    if not python_version or platform_string.startswith("cp3"):
+    if not python_version or platform_string.startswith("cp"):
         return platform_string
 
-    _, _, tail = python_version.partition(".")
-    minor, _, _ = tail.partition(".")
+    major, _, tail = python_version.partition(".")
 
-    return "cp3{}_{}".format(minor, platform_string)
+    return "cp{}{}_{}".format(major, tail, platform_string)
 
 def requirements_files_by_platform(
         *,

python/private/pypi/whl_config_setting.bzl

@@ -35,10 +35,20 @@ def whl_config_setting(*, version = None, config_setting = None, filename = None
         a struct with the validated and parsed values.
     """
     if target_platforms:
-        for p in target_platforms:
+        target_platforms_input = target_platforms
+        target_platforms = []
+        for p in target_platforms_input:
             if not p.startswith("cp"):
                 fail("target_platform should start with 'cp' denoting the python version, got: " + p)
 
+            abi, _, tail = p.partition("_")
+
+            # drop the micro version here, currently there is no usecase to use
+            # multiple python interpreters with the same minor version but
+            # different micro version.
+            abi, _, _ = abi.partition(".")
+            target_platforms.append("{}_{}".format(abi, tail))
+
     return struct(
         config_setting = config_setting,
         filename = filename,

python/private/pypi/whl_library_targets.bzl

@@ -369,26 +369,22 @@ def _config_settings(dependencies_by_platform, native = native, **kwargs):
         if p.startswith("@") or p.endswith("default"):
             continue
 
+        # TODO @aignas 2025-04-20: add tests here
         abi, _, tail = p.partition("_")
         if not abi.startswith("cp"):
             tail = p
             abi = ""
-
         os, _, arch = tail.partition("_")
-        os = "" if os == "anyos" else os
-        arch = "" if arch == "anyarch" else arch
 
         _kwargs = dict(kwargs)
-        if arch:
-            _kwargs.setdefault("constraint_values", []).append("@platforms//cpu:{}".format(arch))
-        if os:
-            _kwargs.setdefault("constraint_values", []).append("@platforms//os:{}".format(os))
+        _kwargs["constraint_values"] = [
+            "@platforms//cpu:{}".format(arch),
+            "@platforms//os:{}".format(os),
+        ]
 
         if abi:
             _kwargs["flag_values"] = {
-                "@rules_python//python/config_settings:python_version_major_minor": "3.{minor_version}".format(
-                    minor_version = abi[len("cp3"):],
-                ),
+                str(Label("//python/config_settings:python_version")): "3.{}".format(abi[len("cp3"):])
             }
 
         native.config_setting(

python/private/pypi/whl_target_platforms.bzl

@@ -75,8 +75,11 @@ def select_whls(*, whls, want_platforms = [], logger = None):
             fail("expected all platforms to start with ABI, but got: {}".format(p))
 
         abi, _, os_cpu = p.partition("_")
+        abi, _, _ = abi.partition(".")
         _want_platforms[os_cpu] = None
-        _want_platforms[p] = None
+
+        # TODO @aignas 2025-04-20: add a test
+        _want_platforms["{}_{}".format(abi, os_cpu)] = None
 
         version_limit_candidate = int(abi[3:])
         if not version_limit: