Hi EmbarrassedSpider34
Long story (see below) short, yes you can ignore this warning :)

Specifically, torch is spinning processes and killing them, every process will have a reference to the parent semaphore (for internal clearml bookkeeping), now python is not very good with this kind of thing (and it is getting better on newer python verions), bottom line python "think" someone lost a semaphore, but there reality is that subprocess never created it in the first place. Does that make sense ?