fix: make versioned rules return both builtin and rules_python providers

CHANGELOG.md

@@ -45,6 +45,9 @@ A brief description of the categories of changes:
 * (rules) User dependencies come before runtime site-packages when using
   {obj}`--bootstrap_impl=script`.
   ([#2064](https://github.com/bazelbuild/rules_python/issues/2064)).
+* (rules) Version-aware rules now return both `@_builtins` and `@rules_python`
+  providers instead of only one.
+  ([#2114](https://github.com/bazelbuild/rules_python/issues/2114)).
 * (pip) Fixed pypi parse_simpleapi_html function for feeds with package metadata
   containing ">" sign
 * (toolchains) Added missing executable permission to

python/config_settings/transition.bzl

@@ -81,31 +81,12 @@ def _transition_py_impl(ctx):
     for k, v in ctx.attr.env.items():
         env[k] = ctx.expand_location(v)
 
-    if PyInfo in target:
-        py_info = target[PyInfo]
-    elif BuiltinPyInfo in target:
-        py_info = target[BuiltinPyInfo]
-    else:
-        fail("target {} does not have rules_python PyInfo or builtin PyInfo".format(target))
-
-    if PyRuntimeInfo in target:
-        py_runtime_info = target[PyRuntimeInfo]
-    elif BuiltinPyRuntimeInfo in target:
-        py_runtime_info = target[BuiltinPyRuntimeInfo]
-    else:
-        fail(
-            "target {} does not have rules_python PyRuntimeInfo or builtin PyRuntimeInfo. ".format(target) +
-            "There is likely no toolchain being matched to your configuration, use --toolchain_resolution_debug parameter to get more information",
-        )
-
     providers = [
         DefaultInfo(
             executable = executable,
             files = depset(default_outputs, transitive = [target[DefaultInfo].files]),
             runfiles = ctx.runfiles(default_outputs).merge(target[DefaultInfo].default_runfiles),
         ),
-        py_info,
-        py_runtime_info,
         # Ensure that the binary we're wrapping is included in code coverage.
         coverage_common.instrumented_files_info(
             ctx,
@@ -118,6 +99,15 @@ def _transition_py_impl(ctx):
         # https://github.com/bazelbuild/bazel/commit/dbdfa07e92f99497be9c14265611ad2920161483
         testing.TestEnvironment(env),
     ]
+    if PyInfo in target:
+        providers.append(target[PyInfo])
+    if BuiltinPyInfo in target and PyInfo != BuiltinPyInfo:
+        providers.append(target[BuiltinPyInfo])
+
+    if PyRuntimeInfo in target:
+        providers.append(target[PyRuntimeInfo])
+    if BuiltinPyRuntimeInfo in target and PyRuntimeInfo != BuiltinPyRuntimeInfo:
+        providers.append(target[BuiltinPyRuntimeInfo])
     return providers
 
 _COMMON_ATTRS = {

tests/config_settings/transition/multi_version_tests.bzl

@@ -16,7 +16,9 @@
 load("@rules_testing//lib:analysis_test.bzl", "analysis_test")
 load("@rules_testing//lib:test_suite.bzl", "test_suite")
 load("@rules_testing//lib:util.bzl", "TestingAspectInfo", rt_util = "util")
+load("//python:py_info.bzl", "PyInfo")
 load("//python/config_settings:transition.bzl", py_binary_transitioned = "py_binary", py_test_transitioned = "py_test")
+load("//python/private:reexports.bzl", "BuiltinPyInfo")  # buildifier: disable=bzl-visibility
 load("//python/private:util.bzl", "IS_BAZEL_7_OR_HIGHER")  # buildifier: disable=bzl-visibility
 
 # NOTE @aignas 2024-06-04: we are using here something that is registered in the MODULE.Bazel
@@ -45,7 +47,8 @@ def _test_py_test_with_transition(name):
 
 def _test_py_test_with_transition_impl(env, target):
     # Nothing to assert; we just want to make sure it builds
-    _ = env, target  # @unused
+    env.expect.that_target(target).has_provider(PyInfo)
+    env.expect.that_target(target).has_provider(BuiltinPyInfo)
 
 _tests.append(_test_py_test_with_transition)
 
@@ -65,7 +68,8 @@ def _test_py_binary_with_transition(name):
 
 def _test_py_binary_with_transition_impl(env, target):
     # Nothing to assert; we just want to make sure it builds
-    _ = env, target  # @unused
+    env.expect.that_target(target).has_provider(PyInfo)
+    env.expect.that_target(target).has_provider(BuiltinPyInfo)
 
 _tests.append(_test_py_binary_with_transition)