feat(bzlmod): enable download_only for experimental_index_url (#2290)

With this change we can support ibazel for building our docs again
because we will just not have any sdists that are causing issues. This
limits the scope to only supporting whls at this time, but for the
time being it is the best solution.

Fixes #2223
Work towards #260

.bazelrc

@@ -4,8 +4,8 @@
 # (Note, we cannot use `common --deleted_packages` because the bazel version command doesn't support it)
 # To update these lines, execute
 # `bazel run @rules_bazel_integration_test//tools:update_deleted_packages`
-build --deleted_packages=examples/build_file_generation,examples/build_file_generation/random_number_generator,examples/bzlmod,examples/bzlmod_build_file_generation,examples/bzlmod_build_file_generation/other_module/other_module/pkg,examples/bzlmod_build_file_generation/runfiles,examples/bzlmod/entry_points,examples/bzlmod/entry_points/tests,examples/bzlmod/libs/my_lib,examples/bzlmod/other_module,examples/bzlmod/other_module/other_module/pkg,examples/bzlmod/patches,examples/bzlmod/py_proto_library,examples/bzlmod/py_proto_library/example.com/another_proto,examples/bzlmod/py_proto_library/example.com/proto,examples/bzlmod/runfiles,examples/bzlmod/tests,examples/bzlmod/tests/other_module,examples/bzlmod/whl_mods,examples/multi_python_versions/libs/my_lib,examples/multi_python_versions/requirements,examples/multi_python_versions/tests,examples/pip_parse,examples/pip_parse_vendored,examples/pip_repository_annotations,examples/py_proto_library,examples/py_proto_library/example.com/another_proto,examples/py_proto_library/example.com/proto,gazelle,gazelle/manifest,gazelle/manifest/generate,gazelle/manifest/hasher,gazelle/manifest/test,gazelle/modules_mapping,gazelle/python,gazelle/pythonconfig,gazelle/python/private,tests/integration/compile_pip_requirements,tests/integration/compile_pip_requirements_test_from_external_repo,tests/integration/custom_commands,tests/integration/ignore_root_user_error,tests/integration/ignore_root_user_error/submodule,tests/integration/local_toolchains,tests/integration/pip_parse,tests/integration/pip_parse/empty,tests/integration/py_cc_toolchain_registered
-query --deleted_packages=examples/build_file_generation,examples/build_file_generation/random_number_generator,examples/bzlmod,examples/bzlmod_build_file_generation,examples/bzlmod_build_file_generation/other_module/other_module/pkg,examples/bzlmod_build_file_generation/runfiles,examples/bzlmod/entry_points,examples/bzlmod/entry_points/tests,examples/bzlmod/libs/my_lib,examples/bzlmod/other_module,examples/bzlmod/other_module/other_module/pkg,examples/bzlmod/patches,examples/bzlmod/py_proto_library,examples/bzlmod/py_proto_library/example.com/another_proto,examples/bzlmod/py_proto_library/example.com/proto,examples/bzlmod/runfiles,examples/bzlmod/tests,examples/bzlmod/tests/other_module,examples/bzlmod/whl_mods,examples/multi_python_versions/libs/my_lib,examples/multi_python_versions/requirements,examples/multi_python_versions/tests,examples/pip_parse,examples/pip_parse_vendored,examples/pip_repository_annotations,examples/py_proto_library,examples/py_proto_library/example.com/another_proto,examples/py_proto_library/example.com/proto,gazelle,gazelle/manifest,gazelle/manifest/generate,gazelle/manifest/hasher,gazelle/manifest/test,gazelle/modules_mapping,gazelle/python,gazelle/pythonconfig,gazelle/python/private,tests/integration/compile_pip_requirements,tests/integration/compile_pip_requirements_test_from_external_repo,tests/integration/custom_commands,tests/integration/ignore_root_user_error,tests/integration/ignore_root_user_error/submodule,tests/integration/local_toolchains,tests/integration/pip_parse,tests/integration/pip_parse/empty,tests/integration/py_cc_toolchain_registered
+build --deleted_packages=examples/build_file_generation,examples/build_file_generation/random_number_generator,examples/bzlmod,examples/bzlmod/entry_points,examples/bzlmod/entry_points/tests,examples/bzlmod/libs/my_lib,examples/bzlmod/other_module,examples/bzlmod/other_module/other_module/pkg,examples/bzlmod/patches,examples/bzlmod/py_proto_library,examples/bzlmod/py_proto_library/example.com/another_proto,examples/bzlmod/py_proto_library/example.com/proto,examples/bzlmod/runfiles,examples/bzlmod/tests,examples/bzlmod/tests/other_module,examples/bzlmod/whl_mods,examples/bzlmod_build_file_generation,examples/bzlmod_build_file_generation/other_module/other_module/pkg,examples/bzlmod_build_file_generation/runfiles,examples/multi_python_versions/libs/my_lib,examples/multi_python_versions/requirements,examples/multi_python_versions/tests,examples/pip_parse,examples/pip_parse_vendored,examples/pip_repository_annotations,examples/py_proto_library,examples/py_proto_library/example.com/another_proto,examples/py_proto_library/example.com/proto,gazelle,gazelle/manifest,gazelle/manifest/generate,gazelle/manifest/hasher,gazelle/manifest/test,gazelle/modules_mapping,gazelle/python,gazelle/python/private,gazelle/pythonconfig,tests/integration/compile_pip_requirements,tests/integration/compile_pip_requirements_test_from_external_repo,tests/integration/custom_commands,tests/integration/ignore_root_user_error,tests/integration/ignore_root_user_error/submodule,tests/integration/local_toolchains,tests/integration/pip_parse,tests/integration/pip_parse/empty,tests/integration/py_cc_toolchain_registered
+query --deleted_packages=examples/build_file_generation,examples/build_file_generation/random_number_generator,examples/bzlmod,examples/bzlmod/entry_points,examples/bzlmod/entry_points/tests,examples/bzlmod/libs/my_lib,examples/bzlmod/other_module,examples/bzlmod/other_module/other_module/pkg,examples/bzlmod/patches,examples/bzlmod/py_proto_library,examples/bzlmod/py_proto_library/example.com/another_proto,examples/bzlmod/py_proto_library/example.com/proto,examples/bzlmod/runfiles,examples/bzlmod/tests,examples/bzlmod/tests/other_module,examples/bzlmod/whl_mods,examples/bzlmod_build_file_generation,examples/bzlmod_build_file_generation/other_module/other_module/pkg,examples/bzlmod_build_file_generation/runfiles,examples/multi_python_versions/libs/my_lib,examples/multi_python_versions/requirements,examples/multi_python_versions/tests,examples/pip_parse,examples/pip_parse_vendored,examples/pip_repository_annotations,examples/py_proto_library,examples/py_proto_library/example.com/another_proto,examples/py_proto_library/example.com/proto,gazelle,gazelle/manifest,gazelle/manifest/generate,gazelle/manifest/hasher,gazelle/manifest/test,gazelle/modules_mapping,gazelle/python,gazelle/python/private,gazelle/pythonconfig,tests/integration/compile_pip_requirements,tests/integration/compile_pip_requirements_test_from_external_repo,tests/integration/custom_commands,tests/integration/ignore_root_user_error,tests/integration/ignore_root_user_error/submodule,tests/integration/local_toolchains,tests/integration/pip_parse,tests/integration/pip_parse/empty,tests/integration/py_cc_toolchain_registered
 
 test --test_output=errors
 

CHANGELOG.md

@@ -68,6 +68,8 @@ A brief description of the categories of changes:
     * `3.12 -> 3.12.7`
 [20241008]: https://github.com/indygreg/python-build-standalone/releases/tag/20241008
 * (coverage) Add support for python 3.13 and bump `coverage.py` to 7.6.1.
+* (bzlmod) Add support for `download_only` flag to disable usage of `sdists`
+  when {bzl:attr}`pip.parse.experimental_index_url` is set.
 
 
 ### Removed

MODULE.bazel

@@ -91,6 +91,7 @@ dev_pip = use_extension(
     dev_dependency = True,
 )
 dev_pip.parse(
+    download_only = True,  # this will not add the `sdist` values to the transitive closures at all.
     hub_name = "dev_pip",
     python_version = "3.11",
     requirements_lock = "//docs:requirements.txt",

python/private/pypi/extension.bzl

@@ -151,9 +151,6 @@ def _create_whl_repos(module_ctx, pip_attr, whl_map, whl_overrides, group_map, s
 
     get_index_urls = None
     if pip_attr.experimental_index_url:
-        if pip_attr.download_only:
-            fail("Currently unsupported to use `download_only` and `experimental_index_url`")
-
         get_index_urls = lambda ctx, distributions: simpleapi_download(
             ctx,
             attr = struct(
@@ -263,11 +260,11 @@ def _create_whl_repos(module_ctx, pip_attr, whl_map, whl_overrides, group_map, s
             is_exposed = False
             for requirement in requirements:
                 is_exposed = is_exposed or requirement.is_exposed
-                for distribution in requirement.whls + [requirement.sdist]:
-                    if not distribution:
-                        # sdist may be None
-                        continue
+                dists = requirement.whls
+                if not pip_attr.download_only and requirement.sdist:
+                    dists = dists + [requirement.sdist]
 
+                for distribution in dists:
                     found_something = True
                     is_hub_reproducible = False
 
@@ -564,6 +561,11 @@ In the future this could be defaulted to `https://pypi.org` when this feature be
 stable.
 
 This is equivalent to `--index-url` `pip` option.
+
+:::{versionchanged} 0.37.0
+If {attr}`download_only` is set, then `sdist` archives will be discarded and `pip.parse` will
+operate in wheel-only mode.
+:::
 """,
         ),
         "experimental_index_url_overrides": attr.string_dict(

tests/pypi/integration/BUILD.bazel

@@ -1,5 +1,5 @@
 load("@bazel_skylib//rules:build_test.bzl", "build_test")
-load("@dev_pip//:requirements.bzl", "all_requirements")
+load("@rules_python_publish_deps//:requirements.bzl", "all_requirements")
 load(":transitions.bzl", "transition_rule")
 
 build_test(