def check_site_dir(self):  # noqa: C901  # is too complex (12)  # FIXME
        """Verify that self.install_dir is .pth-capable dir, if needed"""

        instdir = normalize_path(self.install_dir)
        pth_file = os.path.join(instdir, 'easy-install.pth')

        if not os.path.exists(instdir):
            try:
                os.makedirs(instdir)
            except (OSError, IOError):
                self.cant_write_to_target()

        # Is it a configured, PYTHONPATH, implicit, or explicit site dir?
        is_site_dir = instdir in self.all_site_dirs

        if not is_site_dir and not self.multi_version:
            # No?  Then directly test whether it does .pth file processing
            is_site_dir = self.check_pth_processing()
        else:
            # make sure we can write to target dir
            testfile = self.pseudo_tempname() + '.write-test'
            test_exists = os.path.exists(testfile)
            try:
                if test_exists:
                    os.unlink(testfile)
                open(testfile, 'w').close()
                os.unlink(testfile)
            except (OSError, IOError):
                self.cant_write_to_target()

        if not is_site_dir and not self.multi_version:
            # Can't install non-multi to non-site dir with easy_install
            pythonpath = os.environ.get('PYTHONPATH', '')
            log.warn(self.__no_default_msg, self.install_dir, pythonpath)

        if is_site_dir:
            if self.pth_file is None:
                self.pth_file = PthDistributions(pth_file, self.all_site_dirs)
        else:
            self.pth_file = None

        if self.multi_version and not os.path.exists(pth_file):
            self.pth_file = None  # don't create a .pth file
        self.install_dir = instdir
Verify that self.install_dir is .pth-capable dir, if needed
product/gradle-plugin/src/main/python/setuptools/command/easy_install.py