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 setup_dependent_run_environment(self, env, dependent_spec):
        """Location of the OpenFOAM project directory.
        This is identical to the WM_PROJECT_DIR value, but we avoid that
        variable since it would mask the normal OpenFOAM cleanup of
        previous versions.
        """
        env.set('FOAM_PROJECT_DIR', self.projectdir)