$ fly deploy
INFO Local docker unavailable, hooking you up with a remote Docker builder…
INFO Waiting for remote builder to become available…
5 minutes pass
Error error during connect: Get “http://docker/_ping”: command [ssh -o StrictHostKeyChecking=no -l -p 10000 – fly-builder-patient-feather-6343.fly.dev docker system dial-stdio] has exited with exit status 255, please make sure the URL is valid, and Docker 18.09 or later is installed on the remote host: stderr=ControlPath too long (’/email@example.com:10000’ >= 108 bytes)
When I removed the ControlPath option from my ssh config and ran deploy again, it worked. If there’s a problem with my ssh config I should at least get an error, not a hang. Also, what are you doing with ssh in the first place?