Bug when creating tests with phpunit using namespaces

Test tests/cli/GeneratePhpUnitWithHierarchyPathsCept show the problem.
When I create a test 'codecept generate:phpunit unit SiteTest/Model/Service/Extra, it fails:

PHP Warning:  file_put_contents(/path/tests/SiteTest/Model/Service//SiteTest/Model/Service/ExtraTest.php): failed to open stream: No such file or directory in /path/vendor/codeception/codeception/src/Codeception/Command/Base.php on line 70