mark runtimeenv as build-time venv compatible if python 3.11+

Author: rickeylev

python/private/BUILD.bazel

@@ -86,6 +86,7 @@ bzl_library(
     name = "runtime_env_toolchain_bzl",
     srcs = ["runtime_env_toolchain.bzl"],
     deps = [
+        ":config_settings_bzl",
         ":py_exec_tools_toolchain_bzl",
         ":toolchain_types_bzl",
         "//python:py_runtime_bzl",

python/private/config_settings.bzl

@@ -209,3 +209,33 @@ _current_config = rule(
         "_template": attr.string(default = _DEBUG_ENV_MESSAGE_TEMPLATE),
     },
 )
+
+def is_python_version_at_least(name, **kwargs):
+    flag_name = "_{}_flag".format(name)
+    native.config_setting(
+        name = name,
+        flag_values = {
+            flag_name: "yes",
+        },
+    )
+    _python_version_at_least(
+        name = flag_name,
+        visibility = ["//visibility:private"],
+        **kwargs
+    )
+
+def _python_version_at_least_impl(ctx):
+    at_least = tuple(ctx.attr.at_least.split("."))
+    current = tuple(
+        ctx.attr._major_minor[config_common.FeatureFlagInfo].value.split("."),
+    )
+    value = "yes" if current >= at_least else "no"
+    return [config_common.FeatureFlagInfo(value = value)]
+
+_python_version_at_least = rule(
+    implementation = _python_version_at_least_impl,
+    attrs = {
+        "at_least": attr.string(mandatory = True),
+        "_major_minor": attr.label(default = _PYTHON_VERSION_MAJOR_MINOR_FLAG),
+    },
+)

python/private/runtime_env_toolchain.bzl

@@ -17,6 +17,7 @@ load("@rules_cc//cc:cc_library.bzl", "cc_library")
 load("//python:py_runtime.bzl", "py_runtime")
 load("//python:py_runtime_pair.bzl", "py_runtime_pair")
 load("//python/cc:py_cc_toolchain.bzl", "py_cc_toolchain")
+load("//python/private:config_settings.bzl", "is_python_version_at_least")
 load(":py_exec_tools_toolchain.bzl", "py_exec_tools_toolchain")
 load(":toolchain_types.bzl", "EXEC_TOOLS_TOOLCHAIN_TYPE", "PY_CC_TOOLCHAIN_TYPE", "TARGET_TOOLCHAIN_TYPE")
 
@@ -38,14 +39,19 @@ def define_runtime_env_toolchain(name):
     """
     base_name = name.replace("_toolchain", "")
 
+    supports_build_time_venv = select({
+        ":_is_at_least_py3.11": True,
+        "//conditions:default": False,
+    })
+
     py_runtime(
         name = "_runtime_env_py3_runtime",
         interpreter = "//python/private:runtime_env_toolchain_interpreter.sh",
         python_version = "PY3",
         stub_shebang = "#!/usr/bin/env python3",
         visibility = ["//visibility:private"],
         tags = ["manual"],
-        supports_build_time_venv = False,
+        supports_build_time_venv = supports_build_time_venv,
     )
 
     # This is a dummy runtime whose interpreter_path triggers the native rule
@@ -57,7 +63,7 @@ def define_runtime_env_toolchain(name):
         python_version = "PY3",
         visibility = ["//visibility:private"],
         tags = ["manual"],
-        supports_build_time_venv = False,
+        supports_build_time_venv = supports_build_time_venv,
     )
 
     py_runtime_pair(
@@ -112,3 +118,7 @@ def define_runtime_env_toolchain(name):
         toolchain_type = PY_CC_TOOLCHAIN_TYPE,
         visibility = ["//visibility:public"],
     )
+    is_python_version_at_least(
+        name = "_is_at_least_py3.11",
+        at_least = "3.11",
+    )