Running conditional_fields_features_rebuild() sometimes creates unrecoverable error

The function conditional_fields_dependency_delete() is sometimes called without any dependees. This generate the following error.

Invalid argument supplied for foreach() conditional_fields.module:1164 [warning]
WD php: PDOException: SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual [error]
that corresponds to your MySQL server version for the right syntax to use near ')' at line 1: DELETE FROM {conditional_fields}
WHERE (); Array
(
)
in conditional_fields_dependency_delete() (line 1170 of
sites/all/modules/contrib/conditional_fields/conditional_fields.module).
PDOException: SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ')' at line 1: DELETE FROM {conditional_fields}
WHERE (); Array
(
)
i conditional_fields_dependency_delete() (rad 1170 av sites/all/modules/contrib/conditional_fields/conditional_fields.module).
Drush command terminated abnormally due to an unrecoverable error. [error]