Description:  Maybe not a bug exactly but definitely unclear. So far idempotency has been emphasised that repeating the action produces the same output. But when you have the play 'Non-idempotent approach with the shell module' then no matter how many times you run it you'll end up with a file `/etc/resolv.conf` containing the single line `nameserver 192.0.2.1` in it which is idempotent. If the line given to `cmd` had the `>` character replaced with a `>>` character it would no longer be idempotent as it would add the new line to the file even if the line already existed, is that what was supposed to be there?