Fix import of not-yet-initialized _CONFIG_VARS

python · encukou · Apr 23, 2021 · Oct 15, 2020 · Oct 15, 2020 · Oct 15, 2020
commit 60152550f32ca0fbbb09c2bde4f7522f6bc79d7b
diff --git a/Lib/distutils/sysconfig.py b/Lib/distutils/sysconfig.py
@@ -26,7 +26,6 @@
    _BASE_EXEC_PREFIX as BASE_EXEC_PREFIX,
    _PROJECT_BASE as project_base,
    _PYTHON_BUILD as python_build,
-    _CONFIG_VARS as _config_vars,
    _init_posix as sysconfig_init_posix,
    parse_config_h as sysconfig_parse_config_h,
    _parse_makefile as sysconfig_parse_makefile,
@@ -50,6 +49,12 @@
    get_python_lib,
 )

+# This is better than
+# from sysconfig import _CONFIG_VARS as _config_vars
+# because it makes sure that the global dictionary is initialized
+# which might not be true in the time of import.
+_config_vars = get_config_vars()
+
 if os.name == "nt":
    from sysconfig import _fix_pcbuild

@@ -90,9 +95,7 @@ def customize_compiler(compiler):
            # that Python itself was built on.  Also the user OS
            # version and build tools may not support the same set
            # of CPU architectures for universal builds.
-            global _config_vars
-            # Use get_config_var() to ensure _config_vars is initialized.
-            if not get_config_var('CUSTOMIZED_OSX_COMPILER'):
+            if not _config_vars.get('CUSTOMIZED_OSX_COMPILER'):
                import _osx_support
                _osx_support.customize_compiler(_config_vars)
                _config_vars['CUSTOMIZED_OSX_COMPILER'] = 'True'