I have searched for a few hours on information on this but come up with nothing so apologies if there is a simple answer to this.

The issue is this: I have a pipeline that I disable the default checkout using skipDefaultCheckout() option. This works fine for a branch build however when I run a PR build it seems to be ignored. It looks like any PR build forces a sparse checkout and merges master at the start. This breaks some of my logic later in the pipeline that uses git diff.

Is this a bug or is it desired behavior? It feels like a bug but if it is desired behavior perhaps there is a better way to achieve what I want which I can explain more in detail if this is the right place to do so. (maybe better a question for stackoverflow).