Fix for auto_chmod behavior

[estyrke]

Apparently, in (at least) python 3.5.2, the function that is called on Windows to remove files is os.unlink and not os.remove. This results in permission errors when trying to clean up after easy_install has been used to install a package from a Git repository.

[estyrke]

This is an example of the error (cvtools-1.20rc0.zip is a source distribution that has install_requires=['pyxb'], dependency_links=['git+https://github.com/estyrke/pyxb.git#egg=pyxb-1.2.6-DEV'], in its setup.py).

C:\Users\EmilS\Documents\Code\CvTools>.tox\py35-win64\Scripts\python -m pip -v install .tox\dist\CvTools-1.20rc0.zip
Config variable 'Py_DEBUG' is unset, Python ABI tag may be incorrect
Config variable 'WITH_PYMALLOC' is unset, Python ABI tag may be incorrect
Processing c:\users\emils\documents\code\cvtools\.tox\dist\cvtools-1.20rc0.zip
 Running setup.py (path:C:\Users\EmilS\AppData\Local\Temp\pip-il942ay9-build\setup.py) egg_info for package from file:///C:/Users/EmilS/Documents/Code/CvTools/.tox/dist/CvTools-1.20rc0.zip
   Running command python setup.py egg_info
   C:\Users\EmilS\Documents\Code\CvTools\.tox\py35-win64\lib\site-packages\setuptools\dist.py:333: UserWarning: Normalizing '1.2.6-DEV' to '1.2.6.dev0'
     normalized_version,
   warning: no files found matching 'MANIFEST'
   no previously-included directories found matching 'pyxb\bundles\core\schemas'
   no previously-included directories found matching 'pyxb\bundles\core\remote'
   no previously-included directories found matching 'pyxb\bundles\wssplat\schemas'
   no previously-included directories found matching 'pyxb\bundles\wssplat\remote'
   no previously-included directories found matching 'pyxb\bundles\opengis\schemas'
   no previously-included directories found matching 'pyxb\bundles\opengis\remote'
   no previously-included directories found matching 'doc\_build'
   no previously-included directories found matching 'doc\W3C'
   warning: no previously-included files matching '*~' found anywhere in distribution
   zip_safe flag not set; analyzing archive contents...
   pyxb.namespace.__pycache__.archive.cpython-35: module references __file__
   pyxb.utils.__pycache__.six.cpython-35: module references __path__

   Installed c:\users\emils\appdata\local\temp\pip-il942ay9-build\.eggs\pyxb-1.2.6.dev0-py3.5.egg
   Traceback (most recent call last):
     File "C:\Users\EmilS\Documents\Code\CvTools\.tox\py35-win64\lib\shutil.py", line 381, in _rmtree_unsafe
       os.unlink(fullname)
   PermissionError: [WinError 5] ┼tkomst nekad: 'C:\\Users\\EmilS\\AppData\\Local\\Temp\\easy_install-pj7vbsqv\\pyxb.git\\.git\\objects\\pack\\pack-7320a85cb6c0d30cdfd68b3b269fb97b5bd49e39.idx'

   During handling of the above exception, another exception occurred:

   Traceback (most recent call last):
     File "<string>", line 1, in <module>
     File "C:\Users\EmilS\AppData\Local\Temp\pip-il942ay9-build\setup.py", line 126, in <module>
       "build_xsd = __main__:BuildXsdCommand",
     File "C:\Users\EmilS\AppData\Local\Continuum\Miniconda3\Lib\distutils\core.py", line 108, in setup
       _setup_distribution = dist = klass(attrs)
     File "C:\Users\EmilS\Documents\Code\CvTools\.tox\py35-win64\lib\site-packages\setuptools\dist.py", line 317, in __init__
       self.fetch_build_eggs(attrs['setup_requires'])
     File "C:\Users\EmilS\Documents\Code\CvTools\.tox\py35-win64\lib\site-packages\setuptools\dist.py", line 372, in fetch_build_eggs
       replace_conflicting=True,
     File "C:\Users\EmilS\Documents\Code\CvTools\.tox\py35-win64\lib\site-packages\pkg_resources\__init__.py", line 851, in resolve
       dist = best[req.key] = env.best_match(req, ws, installer)
     File "C:\Users\EmilS\Documents\Code\CvTools\.tox\py35-win64\lib\site-packages\pkg_resources\__init__.py", line 1123, in best_match
       return self.obtain(req, installer)
     File "C:\Users\EmilS\Documents\Code\CvTools\.tox\py35-win64\lib\site-packages\pkg_resources\__init__.py", line 1135, in obtain
       return installer(requirement)
     File "C:\Users\EmilS\Documents\Code\CvTools\.tox\py35-win64\lib\site-packages\setuptools\dist.py", line 440, in fetch_build_egg
       return cmd.easy_install(req)
     File "C:\Users\EmilS\Documents\Code\CvTools\.tox\py35-win64\lib\site-packages\setuptools\command\easy_install.py", line 674, in easy_install
       return self.install_item(spec, dist.location, tmpdir, deps)
     File "C:\Users\EmilS\AppData\Local\Continuum\Miniconda3\Lib\contextlib.py", line 66, in __exit__
       next(self.gen)
     File "C:\Users\EmilS\Documents\Code\CvTools\.tox\py35-win64\lib\site-packages\setuptools\command\easy_install.py", line 638, in _tmpdir
       os.path.exists(tmpdir) and rmtree(rmtree_safe(tmpdir))
     File "C:\Users\EmilS\Documents\Code\CvTools\.tox\py35-win64\lib\site-packages\setuptools\command\easy_install.py", line 2233, in rmtree
       return shutil.rmtree(path, ignore_errors, onerror)
     File "C:\Users\EmilS\Documents\Code\CvTools\.tox\py35-win64\lib\shutil.py", line 488, in rmtree
       return _rmtree_unsafe(path, onerror)
     File "C:\Users\EmilS\Documents\Code\CvTools\.tox\py35-win64\lib\shutil.py", line 378, in _rmtree_unsafe
       _rmtree_unsafe(fullname, onerror)
     File "C:\Users\EmilS\Documents\Code\CvTools\.tox\py35-win64\lib\shutil.py", line 378, in _rmtree_unsafe
       _rmtree_unsafe(fullname, onerror)
     File "C:\Users\EmilS\Documents\Code\CvTools\.tox\py35-win64\lib\shutil.py", line 378, in _rmtree_unsafe
       _rmtree_unsafe(fullname, onerror)
     File "C:\Users\EmilS\Documents\Code\CvTools\.tox\py35-win64\lib\shutil.py", line 378, in _rmtree_unsafe
       _rmtree_unsafe(fullname, onerror)
     File "C:\Users\EmilS\Documents\Code\CvTools\.tox\py35-win64\lib\shutil.py", line 383, in _rmtree_unsafe
       onerror(os.unlink, fullname, sys.exc_info())
     File "C:\Users\EmilS\Documents\Code\CvTools\.tox\py35-win64\lib\site-packages\setuptools\command\easy_install.py", line 1683, in auto_chmod
       six.reraise(et, (ev[0], ev[1] + (" %s %s" % (func, arg))))
   TypeError: 'PermissionError' object is not subscriptable
   auto_chmod
Cleaning up...
Command "python setup.py egg_info" failed with error code 1 in C:\Users\EmilS\AppData\Local\Temp\pip-il942ay9-build\
Exception information:
Traceback (most recent call last):
 File "C:\Users\EmilS\Documents\Code\CvTools\.tox\py35-win64\lib\site-packages\pip\basecommand.py", line 215, in main
   status = self.run(options, args)
 File "C:\Users\EmilS\Documents\Code\CvTools\.tox\py35-win64\lib\site-packages\pip\commands\install.py", line 335, in run
   wb.build(autobuilding=True)
 File "C:\Users\EmilS\Documents\Code\CvTools\.tox\py35-win64\lib\site-packages\pip\wheel.py", line 749, in build
   self.requirement_set.prepare_files(self.finder)
 File "C:\Users\EmilS\Documents\Code\CvTools\.tox\py35-win64\lib\site-packages\pip\req\req_set.py", line 380, in prepare_files
   ignore_dependencies=self.ignore_dependencies))
 File "C:\Users\EmilS\Documents\Code\CvTools\.tox\py35-win64\lib\site-packages\pip\req\req_set.py", line 634, in _prepare_file
   abstract_dist.prep_for_dist()
 File "C:\Users\EmilS\Documents\Code\CvTools\.tox\py35-win64\lib\site-packages\pip\req\req_set.py", line 129, in prep_for_dist
   self.req_to_install.run_egg_info()
 File "C:\Users\EmilS\Documents\Code\CvTools\.tox\py35-win64\lib\site-packages\pip\req\req_install.py", line 439, in run_egg_info
   command_desc='python setup.py egg_info')
 File "C:\Users\EmilS\Documents\Code\CvTools\.tox\py35-win64\lib\site-packages\pip\utils\__init__.py", line 707, in call_subprocess
   % (command_desc, proc.returncode, cwd))
pip.exceptions.InstallationError: Command "python setup.py egg_info" failed with error code 1 in C:\Users\EmilS\AppData\Local\Temp\pip-il942ay9-build\

[estyrke]

The corresponding check in pip looks a bit different - that might be another option: https://github.com/pypa/pip/blob/9.0.1/pip/utils/__init__.py#L105