On the FAQ page you have a list of commands, one for each algorithm. However when I have ethminer in that list it never gets passed that:

  ℹ  20:48:47|ethminer  Connecting to stratum server europe.equihash-hub.miningpoolhub.com:12023
  ℹ  20:48:47|stratum   Connected to stratum server europe.equihash-hub.miningpoolhub.com : 12023
  ℹ  20:48:47|stratum   Starting farm
 cl  20:48:47|cl-0      No work. Pause for 3 s.
 cl  20:48:47|cl-1      No work. Pause for 3 s.
  ℹ  20:48:47|stratum   Subscribed to stratum server
  ℹ  20:48:47|stratum   Worker not authorized: myuser.first
  ℹ  20:48:47|stratum   Disconnecting
  ℹ  20:48:47|stratum   Stopping farm
 cl  20:48:50|cl-0      No work. Pause for 3 s.
 cl  20:48:50|cl-1      No work. Pause for 3 s.
 cl  20:48:53|cl-0      No work. Pause for 3 s.
 cl  20:48:53|cl-1      No work. Pause for 3 s.
 cl  20:48:56|cl-0      No work. Pause for 3 s.
 cl  20:48:56|cl-1      No work. Pause for 3 s.

how to make sure ethminer exists? I have:
~/ethminer -FF exit --farm-retries 0 -G -S europe.equihash-hub.miningpoolhub.com:12023 -O ${USERNAME}.${WORKERNAME}:x -FS exit

thank you