World Partition Conversion Issues

I’ve found the relevant code that’s producing the log line:

if (!FPackageName::SearchForPackageOnDisk(Tokens[0], &Tokens[0]))
{
	UE_LOG(LogWorldPartitionConvertCommandlet, Error, TEXT("Unknown level '%s'"), *Tokens[0]);
	return 1;
}

But I can’t for the life of me figure out what the proper Long or Short Package name is!