Hi,
The Whoosh search backend is no more supported ( https://code.rhodecode.com/rhodecode-enterprise-ce/files/main/rhodecode/lib/index/\__init_\_.py?at=main#L151 ) as explicitly stipulated by the documentation at Full-text Search - RhodeCode Enterprise 5.7.0 documentation and Full-text Search - RhodeCode rcstack 5.27.5 documentation .
But the configuration is still provided as an alternative within the Configuration of components - RhodeCode rcstack 5.27.5 documentation documentation page.