> I think you did not get the latest version of my code.
I pulled and updated again and got a different error :)

ERROR: test_install_wrapper_scripts (packaging.tests.test_command_build_scripts.BuildScriptsTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "Lib/packaging/tests/test_command_build_scripts.py", line 79, in test_install_wrapper_scripts
    with open(script, "rb") as f:
IOError: [Errno 13] Permission denied: '/tmp/user/1013/tmp2xp9qc/tmpwhzzmg/script1'

(/tmp/user/1013 is my $TMP directory)

>> The new scripts feature should reuse the already existing scripts
>> field, in the files section.
> But they have different string syntax

Yes, you will have to update the config file parsing code in config, code that uses dist.scripts, etc.