The sshca_sign plugin does not support check mode
Example error trace:
TASK [base : Generate SSH host key] *********************************************************************************************************************************************************
ok: [host1] => (item=ed25519)
Tuesday 30 April 2019 09:02:46 +0100 (0:00:00.282) 0:00:56.282 *********
TASK [base : Sign SSH host key] *************************************************************************************************************************************************************
An exception occurred during task execution. To see the full traceback, use -vvv. The error was: KeyError: 'rc'
fatal: [host1]: FAILED! => {"msg": "Unexpected failure during module execution.", "stdout": ""}
Tuesday 30 April 2019 09:02:47 +0100 (0:00:00.455) 0:00:56.738 *********