This is what I'm getting:

and then it eventually exits
It all looks right, maybe it's a worker/account issue.
maybe just as a test try
sgminer -k darkcoin -o stratum+tcp://east01.us.trademybit.com:4440 -u dmpotter.test -p x -X 4
I'm an idiot. There was a typo that I had somehow missed even after going over it like 30 times... lol