Hmmm...I can't list, chmod, move, or do anything with .cache/tracker, not even after devel-su. That results "Permissions denied". Diretory has rights "d---rwx--- metadata metadata"

That looks very suspicious. Do you have any advise how to destroy that directory?

By the way, uninstalling package smartsearch is not viable option to smartsearch problem. That would remove quite a bunch OS related packages also.