make_dict with mandatory option

tiramisu/config.py

@@ -575,13 +575,17 @@ class SubConfig(object):
                                      withvalue,
                                      fullpath,
                                      pathsvalues)
-            except PropertiesOptionError:
+            except PropertiesOptionError as err:
+                if err.proptype == ['mandatory']:
+                    raise err
                 pass
         else:
             try:
                 ret = self.getattr(name,
                                    option_bag)
-            except PropertiesOptionError:
+            except PropertiesOptionError as err:
+                if err.proptype == ['mandatory']:
+                    raise err
                 return
             if flatten:
                 name_ = option.impl_getname()