public static String substVars(String val, PropertyContainer pc1) throws ScanException {
        return substVars(val, pc1, null);
    }
@Test
    public void jackrabbit_standalone() throws ScanException {
        String r = OptionHelper.substVars("${jackrabbit.log:-${repo:-jackrabbit}/log/jackrabbit.log}", context);
        assertEquals("jackrabbit/log/jackrabbit.log", r);
    }