There is likely something blocking this deploy. If it’s hung, try running this:
fly status --all
See if there are any failed instances, or instances that don’t have health check information.
Also, if the app has volumes, it’s possible it got hung trying to do a canary deploy. Canary deploys will wait like this until a previous VM stops when you have volumes. This generally shouldn’t happen because we try to default to rolling deploys, but there are edge cases where it crops up.
You can potentially unstick your deploy by running fly vm stop <id>. Use any old instance ID and see if it helps.