As a way of implementing conditionals, you could currently do something like:

def fail_on_true(check_val, pass_through_val): if check_val: raise Exception("Expected failure") return pass_through_val exp_fail = Function(function=fail_on_true)

You could then insert this node before the node/sub-workflow you wish to skip on some condition.

If we promoted this to a proper interface, we could then check for it to avoid creating crash files and printing the error.

(From discussion with @tclose.)