SSHKit::Runner::ExecuteError: Exception while executing as ... agent could not sign data with requested identity

I can't deploy to all bitmask nodes all together. It always breaks at random nodes:

--- git/bitmask ‹master* ⁇› » leap deploy        
Deploying to these nodes: millipede, newt, elephant, diplocaulus, tuatara, otter, giraffe, lynx, ant, donkey, leech, clam, local1, aardwolf, dotterel, demodex, cat, orangutan, alpaca, snail
Continue? y
 = checking nodes
   - [giraffe] ok
   - [newt] ok
   - [elephant] ok
   - [otter] ok
   - [donkey] ok
   - [diplocaulus] ok
   - [tuatara] ok
   - [millipede] ok


   - error SSHKit::Runner::ExecuteError: Exception while executing as root@lynx.cdev.bitmask.net: agent could not sign data with requested identity

--- git/bitmask ‹master* ⁇› » leap deploy                                                                                                                                                                      1 ↵
Deploying to these nodes: millipede, newt, elephant, diplocaulus, tuatara, otter, giraffe, lynx, ant, donkey, leech, clam, local1, aardwolf, dotterel, demodex, cat, orangutan, alpaca, snail
Continue? y
 = checking nodes
   - [lynx] ok
   - [newt] ok
   - [elephant] ok
   - [giraffe] ok
   - [otter] ok
   - [donkey] ok
   - [tuatara] ok
   - [ant] ok
   - [millipede] ok


   - error SSHKit::Runner::ExecuteError: Exception while executing as root@diplocaulus.bitmask.net: agent could not sign data with requested identity

--- git/bitmask ‹master* ⁇› » leap deploy                                                                                                                                                                      1 ↵
Deploying to these nodes: millipede, newt, elephant, diplocaulus, tuatara, otter, giraffe, lynx, ant, donkey, leech, clam, local1, aardwolf, dotterel, demodex, cat, orangutan, alpaca, snail
Continue? y
 = checking nodes
   - [elephant] ok
   - [newt] ok
   - [giraffe] ok
   - [donkey] ok
   - [diplocaulus] ok
   - [tuatara] ok
   - [millipede] ok


   - error SSHKit::Runner::ExecuteError: Exception while executing as root@otter.demo.bitmask.net: agent could not sign data with requested identity