if one annotates the inside of a field in an Enum then it will block evaluation of follow up fields on failure.

#[derive(FromPest, Debug, Clone,)]
#[pest_ast(rule(Rule::Formula))]
pub enum Formula {
    Idfr(#[pest_ast(inner(with(span_into_string)))] String),
   OtherField(Other)
}

I have a commit that solves the issue
65a77e1
are you interested in a pr?