Trellis SSH Key Forwarding Error

gistfile1.txt

TASK [deploy : Add known_hosts] ************************************************
System info:
  Ansible 2.2.1.0; Darwin
  Trellis at "Check Ansible version before Ansible validates task attributes"
---------------------------------------------------
ssh-keygen failed (rc=255,stdout='',stderr='do_known_hosts: hostkeys_foreach
failed: Permission denied
')
failed: [staging.OMITTED.com] (item=github.com ssh-rsa OMITTED==) => {"failed": true, "item": "github.com ssh-rsa OMITTED=="}
---------------------------------------------------
ssh-keygen failed (rc=255,stdout='',stderr='do_known_hosts: hostkeys_foreach
failed: Permission denied
')
failed: [staging.OMITTED.com] (item=bitbucket.org ssh-rsa OMITTED==) => {"failed": true, "item": "bitbucket.org ssh-rsa OMITTED=="}
---------------------------------------------------
ssh-keygen failed (rc=255,stdout='',stderr='do_known_hosts: hostkeys_foreach
failed: Permission denied
')
failed: [staging.OMITTED.com] (item=gitlab.com ssh-ed25519 OMITTED) => {"failed": true, "item": "gitlab.com ssh-ed25519 OMITTED"}
---------------------------------------------------
ssh-keygen failed (rc=255,stdout='',stderr='do_known_hosts: hostkeys_foreach
failed: Permission denied
')
failed: [staging.OMITTED.com] (item=gitlab.com ssh-rsa OMITTED) => {"failed": true, "item": "gitlab.com ssh-rsa OMITTED"}