"Semantic error: Error when calling primitive pop (my_table -> untag -> pop) line 20: argument 1 has type field, but formal count has type integer value"

pop_all.txt

// Metadata to count number of labels
header_type ingress_metadata_t {
    fields {
        count : 32;
    }
}

// Count number of labels in the stack
parser parse_label {
    extract(label_stack[next]);
    set_metadata(ingress_metadata.count, (ingress_metadata.count + 1));
    return select(latest.bos) {
        0 : parse_label;
        1 : ingress;
    }
}

// Remove all labels
action untag() {
	pop(label_stack, ingress_metadata.count);
}