As the tempfile step is skipped in check mode, the resulting path is undefined. e.g:
(undercloud) [stack@undercloud ~]$ ansible-playbook --check foo.yaml
[WARNING]: provided hosts list is empty, only localhost is available. Note that the implicit localhost
does not match 'all'
PLAY [localhost] ****************************************************************************************
TASK [Gathering Facts] **********************************************************************************
ok: [localhost]
TASK [Create temporary file for ssh_known_hosts] ********************************************************
skipping: [localhost]
TASK [Create a temporary copy of ssh_known_hosts] *******************************************************
fatal: [localhost]: FAILED! => {"msg": "The task includes an option with an undefined variable. The error was: 'dict object' has no attribute 'path'\n\nThe error appears to have been in '/home/stack/foo.yaml': line 13, column 11, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n register: ssh_known_hosts_tmp\n - name: Create a temporary copy of ssh_known_hosts\n ^ here\n"}
to retry, use: --limit @/home/stack/foo.retry
PLAY RECAP **********************************************************************************************
localhost : ok=1 changed=0 unreachable=0 failed=1
The entire block of tasks should be skipped in check mode.
Fix proposed to branch: master
Review: https:/