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 parse(self):
		f = tempfile.NamedTemporaryFile(delete=True)
		cmd_str = "curl http://pkgs.fedoraproject.org/cgit/rpms/%s.git/plain/%s.spec > %s"
		runCommand(cmd_str % (self.package, self.package, f.name))
		self.sp_obj = SpecParser(f.name)
		if not self.sp_obj.parse():
			self.err = self.sp_obj.getError()
			f.close()
			return False

		f.close()
		return True