def coerce(cls, string):
        """Create a :class:`Requirement` object from a given package spec."""
        match = re.match(cls.spec_regex, string)
        if not match:
            raise InvalidRequirementSpecError("could not parse requirement")
        package = match.group(1)
        if all(match.group(2, 3)):
            version = "".join(match.group(2, 3))
        else:
            version = None
        return cls(package, version)
def export(self, location, url):
        # type: (str, HiddenText) -> None
        """Export the Git repository at the url to the destination location"""
        if not location.endswith('/'):
            location = location + '/'

        with TempDirectory(kind="export") as temp_dir:
            self.unpack(temp_dir.path, url=url)
            self.run_command(
                ['checkout-index', '-a', '-f', '--prefix', location],
                show_stdout=False, cwd=temp_dir.path
            )