[pull] main from bazel-contrib:main

.bazelrc

@@ -5,6 +5,10 @@
 # To update the file, execute
 import %workspace%/.bazelrc.deleted_packages
 
+# Symlinks are used extensively because of runfiles, venvs, and other reasons.
+# Supporting otherwise is very complex with little benefit.
+startup --windows_enable_symlinks
+
 test --test_output=errors
 
 # Do NOT implicitly create empty __init__.py files in the runfiles tree.

CHANGELOG.md

@@ -58,6 +58,13 @@ END_UNRELEASED_TEMPLATE
 
 {#v0-0-0-changed}
 ### Changed
+
+**Breaking**
+* {obj}`--windows_enable_symlinks` is required. Add `startup
+  --windows_enable_symlinks` to your `.bazelrc` to enable Bazel using full
+  symlink support on Windows.
+
+Other changes:
 * (pypi) Update dependencies used for `compile_pip_requirements`, building
   sdists in the `whl_library` rule and fetching wheels using `pip`.
 
@@ -70,7 +77,10 @@ END_UNRELEASED_TEMPLATE
 
 {#v0-0-0-added}
 ### Added
-* Nothing added.
+* (pypi) Write SimpleAPI contents to the `MODULE.bazel.lock` file if using
+  {obj}`experimental_index_url` which should speed up consecutive initializations and should no
+  longer require the network access if the cache is hydrated.
+  Implements [#2731](https://github.com/bazel-contrib/rules_python/issues/2731).
 
 {#v1-9-0}
 ## [1.9.0] - 2026-02-21

python/private/pypi/BUILD.bazel

@@ -359,6 +359,9 @@ bzl_library(
 bzl_library(
     name = "pypi_cache_bzl",
     srcs = ["pypi_cache.bzl"],
+    deps = [
+        ":version_from_filename_bzl",
+    ],
 )
 
 bzl_library(

python/private/pypi/extension.bzl

@@ -225,7 +225,7 @@ You cannot use both the additive_build_content and additive_build_content_file a
     # dict[str repo, HubBuilder]
     # See `hub_builder.bzl%hub_builder()` for `HubBuilder`
     pip_hub_map = {}
-    simpleapi_cache = pypi_cache()
+    simpleapi_cache = pypi_cache(mctx = module_ctx)
 
     for mod in module_ctx.modules:
         for pip_attr in mod.tags.parse:
@@ -293,6 +293,7 @@ You cannot use both the additive_build_content and additive_build_content_file a
         config = config,
         exposed_packages = exposed_packages,
         extra_aliases = extra_aliases,
+        facts = simpleapi_cache.get_facts(),
         hub_group_map = hub_group_map,
         hub_whl_map = hub_whl_map,
         whl_libraries = whl_libraries,
@@ -372,7 +373,11 @@ def _pip_impl(module_ctx):
         module_ctx: module contents
     """
 
-    mods = parse_modules(module_ctx, enable_pipstar = rp_config.enable_pipstar, enable_pipstar_extract = rp_config.enable_pipstar and rp_config.bazel_8_or_later)
+    mods = parse_modules(
+        module_ctx,
+        enable_pipstar = rp_config.enable_pipstar,
+        enable_pipstar_extract = rp_config.enable_pipstar and rp_config.bazel_8_or_later,
+    )
 
     # Build all of the wheel modifications if the tag class is called.
     _whl_mods_impl(mods.whl_mods)
@@ -394,9 +399,15 @@ def _pip_impl(module_ctx):
             groups = mods.hub_group_map.get(hub_name),
         )
 
-    return module_ctx.extension_metadata(
-        reproducible = True,
-    )
+    # The code is smart to not return facts if we don't support the mechanism for that.
+    # Hence we should not pass it to the metadata
+    if mods.facts:
+        return module_ctx.extension_metadata(
+            reproducible = True,
+            facts = mods.facts,
+        )
+    else:
+        return module_ctx.extension_metadata(reproducible = True)
 
 _default_attrs = {
     "arch_name": attr.string(

python/private/pypi/hub_builder.bzl

@@ -395,11 +395,11 @@ def _set_get_index_urls(self, pip_attr):
             index_url = pip_attr.experimental_index_url,
             extra_index_urls = pip_attr.experimental_extra_index_urls or [],
             index_url_overrides = pip_attr.experimental_index_url_overrides or {},
-            sources = [
-                d
-                for d in distributions
+            sources = {
+                d: versions
+                for d, versions in distributions.items()
                 if _use_downloader(self, python_version, d)
-            ],
+            },
             envsubst = pip_attr.envsubst,
             # Auth related info
             netrc = pip_attr.netrc,

python/private/pypi/parse_requirements.bzl

@@ -53,7 +53,7 @@ def parse_requirements(
             os, arch combinations.
         extra_pip_args (string list): Extra pip arguments to perform extra validations and to
             be joined with args found in files.
-        get_index_urls: Callable[[ctx, list[str]], dict], a callable to get all
+        get_index_urls: Callable[[ctx, dict[str, list[str]]], dict], a callable to get all
             of the distribution URLs from a PyPI index. Accepts ctx and
             distribution names to query.
         evaluate_markers: A function to use to evaluate the requirements.
@@ -170,15 +170,17 @@ def parse_requirements(
 
     index_urls = {}
     if get_index_urls:
+        distributions = {}
+        for reqs in requirements_by_platform.values():
+            for req in reqs.values():
+                if req.srcs.url:
+                    continue
+
+                distributions.setdefault(req.distribution, []).append(req.srcs.version)
+
         index_urls = get_index_urls(
             ctx,
-            # Use list({}) as a way to have a set
-            list({
-                req.distribution: None
-                for reqs in requirements_by_platform.values()
-                for req in reqs.values()
-                if not req.srcs.url
-            }),
+            distributions,
         )
 
     ret = []
@@ -267,7 +269,7 @@ def _package_srcs(
                     url = "",
                     filename = "",
                     sha256 = "",
-                    yanked = False,
+                    yanked = None,
                 )
                 req_line = r.srcs.requirement_line
             else:
@@ -379,7 +381,7 @@ def _add_dists(*, requirement, index_urls, target_platform, logger = None):
             url = requirement.srcs.url,
             filename = requirement.srcs.filename,
             sha256 = requirement.srcs.shas[0] if requirement.srcs.shas else "",
-            yanked = False,
+            yanked = None,
         )
 
         return dist, False
@@ -403,20 +405,20 @@ def _add_dists(*, requirement, index_urls, target_platform, logger = None):
         # See https://packaging.python.org/en/latest/specifications/simple-repository-api/#adding-yank-support-to-the-simple-api
 
         maybe_whl = index_urls.whls.get(sha256)
-        if maybe_whl and not maybe_whl.yanked:
+        if maybe_whl and maybe_whl.yanked == None:
             whls.append(maybe_whl)
             continue
 
         maybe_sdist = index_urls.sdists.get(sha256)
-        if maybe_sdist and not maybe_sdist.yanked:
+        if maybe_sdist and maybe_sdist.yanked == None:
             sdist = maybe_sdist
             continue
 
         logger.warn(lambda: "Could not find a whl or an sdist with sha256={}".format(sha256))
 
     yanked = {}
     for dist in whls + [sdist]:
-        if dist and dist.yanked:
+        if dist and dist.yanked != None:
             yanked.setdefault(dist.yanked, []).append(dist.filename)
     if yanked:
         logger.warn(lambda: "\n".join([