flake8: fix style issues to build_scripts, amended: fix main.py

This cosmetic change caused plain Python builds without virtual env
to break, again. The change was sorting the imports of main.py
in some arbitrary way that caused problems.

It would be much more convenient if changes to the setup scripts
were tested with and without venv or virtualenv. These repeated
errors are an annoying waste of time.

Change-Id: I84335be874cc96128fa192a288a8a7909af13e99
Fixes: PYSIDE-1760
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
(cherry picked from commit dc55de238c0c7c52812ec4203471e4b2a7f0805d)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

1 files changed, 14 insertions, 12 deletions

diff --git a/build_scripts/main.py b/build_scripts/main.py
index 65ddca716..b4576d0e8 100644
--- a/build_scripts/main.py
+++ b/build_scripts/main.py
@@ -43,28 +43,30 @@ import platform
 import re
 import sys
 import time
+from packaging.version import parse as parse_version
 from pathlib import Path
 from shutil import which, copytree
 from textwrap import dedent
 
-import setuptools  # Import setuptools before distutils
-# PYSIDE-1760: Although not used here, pre-load this module early to avoid
-#              a racing condition with the import order. Note that this problem
-#              happens only with custom builds of Python without virtual environment.
-import setuptools.command.install_scripts
-from packaging.version import parse as parse_version
+# PYSIDE-1760: Pre-load setuptools modules early to avoid racing conditions.
+#              Please be careful: All setuptools modules must be loaded before _distutils
+#              may be touched (should be avoided anyway, btw.)
+# Note: This bug is only visible when tools like pyenv are not used. They have some
+#       pre-loading effect so that setuptools is already in the cache, hiding the problem.
 from setuptools import Command, Extension
-from setuptools._distutils import log
-from setuptools._distutils import sysconfig as sconfig
-from setuptools._distutils.command.build import build as _build
-# Use the distutils implementation within setuptools
-from setuptools._distutils.errors import DistutilsSetupError
 from setuptools.command.bdist_egg import bdist_egg as _bdist_egg
 from setuptools.command.build_ext import build_ext as _build_ext
 from setuptools.command.build_py import build_py as _build_py
 from setuptools.command.develop import develop as _develop
 from setuptools.command.install import install as _install
 from setuptools.command.install_lib import install_lib as _install_lib
+from setuptools.command.install_scripts import install_scripts  # preload only
+
+# Use the distutils implementation within setuptools (but not before)
+from setuptools._distutils import log
+from setuptools._distutils import sysconfig as sconfig
+from setuptools._distutils.command.build import build as _build
+from setuptools._distutils.errors import DistutilsSetupError
 
 from .build_info_collector import BuildInfoCollectorMixin
 from .config import config
@@ -640,7 +642,7 @@ class PysideBuild(_build, DistUtilsCommandMixin, BuildInfoCollectorMixin):
         if OPTION['NO_QT_TOOLS']:
             cmake_cmd.append("-DNO_QT_TOOLS=yes")
         if OPTION['SKIP_DOCS']:
-            log.info(f"Warning: '--skip-docs' is deprecated and will be removed. "
+            log.info("Warning: '--skip-docs' is deprecated and will be removed. "
                      "The documentation is not built by default")
         if OPTION['BUILD_DOCS']:
             cmake_cmd.append("-DBUILD_DOCS=yes")