based on the upstream commit aa8430ad391d93391988451f43ecedd76ca4dd77

diff -Naur wxPython-4.0.7.post2.orig/setup.py wxPython-4.0.7.post2/setup.py
--- wxPython-4.0.7.post2.orig/setup.py	2019-11-12 03:54:31.000000000 +0100
+++ wxPython-4.0.7.post2/setup.py	2020-11-05 19:00:12.489380000 +0100
@@ -11,6 +11,7 @@
 
 import sys, os
 import glob
+import stat
 
 from setuptools                     import setup, find_packages
 from distutils.command.build        import build as orig_build
@@ -306,7 +307,15 @@
 orig_copy_tree = distutils.dir_util.copy_tree
 distutils.dir_util.copy_tree = wx_copy_tree
 
+# Monkey-patch make_writeable too. Sometimes the link is copied before the
+# target, and the original make_writable will fail on a link to a missing
+# target.
+def wx_make_writable(target):
+    if not os.path.islink(target):
+        os.chmod(target, os.stat(target).st_mode | stat.S_IWRITE)
 
+import setuptools.command.build_py
+setuptools.command.build_py.make_writable = wx_make_writable
 
 #----------------------------------------------------------------------