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 config(self):
        settings = {
            # Use SYSTEMMPI since openfoam-org doesn't have USERMPI
            'mplib': 'SYSTEMMPI',

            # Add links into bin/, lib/ (eg, for other applications)
            'link': False,
        }
        # OpenFOAM v2.4 and earlier lacks WM_LABEL_OPTION
        if self.spec.satisfies('@:2.4'):
            settings['label-size'] = False
        return settings