The arc diff takes some rules as input with --base. Due to our workflow, I am using a script that holds three rules. If one fails, the next will be performed. Unfortunately, I am not able to find a way to skip the arc:prompt rule. If no valid commit ID was entered, the rule should fail and the following rule should be executed. My example is the following:

arc diff --base "arc:exec(type .bookmark), arc:prompt, arc:upstream" --no-amend

.bookmark is a file containing a stored commit id. (find is cat in Windows.) I would like to take a look at this for my self and diff it to the repository, but I was not able to find the code where the rules are evaluated.