Some yaml linters like in Symfony trow errors on this because it’s a duplicate key. I just want to know if this is valid in Drone, or you can use different keys for the git checkout. If this is only possible with duplicate keys I’ll have to use a yaml linter that doesn’t fall over this.
Duplicate keys are invalid per the official yaml specification, however, Drone supports them in version 0.8. Drone 1.0 is more compliant with the specification, and will error if a yaml file has duplicate keys.
You are using the 0.8 yaml format which means duplicate keys are supported. The 1.0 yaml format completely changed. Many of the questions you are asking do not really apply to the 1.0 yaml format. To learn more about the 1.0 yaml format see https://docs.drone.io/user-guide/pipeline/