def _assert_requirements(self):
        macos_version = platform.mac_ver()[0]

        if 9 < int(macos_version.split(".")[1]):
            raise UnsupportedOSError(
                "Unsupported OS version; please upgrade to 10.9 or later "
                "and try again.",
                macos_version
            )

        if not self._has_xcode_tools():
            print(tty.progress("Installing the Command Line Tools (expect a "
                               "GUI popup):"))
            spawn(["/usr/bin/xcode-select", "--install"],
                  debug=self.debug, env=self.env)
            click.pause("Press any key when the installation is complete.")
            if not self._has_xcode_tools():
                raise XcodeMissingError(
                    "Aborted Command Line Tools installation.",
                )

        if spawn(["which", "brew"], check_call=False, debug=self.debug,
                 stdout=subprocess.PIPE,
                 stderr=subprocess.PIPE,
                 env=self.env):
            raise BrewMissingError(
                "Homebrew not installed",
                "http://brew.sh/#install"
            )
dataset/ETHPy150Open msanders/cider/cider/core.py/Cider._assert_requirements/swapped operands of `<`