Function diff_base_error 

fn diff_base_error<'a>(
    refresh: Option<&'a BaseRefresh>,
    stored_error: Option<&'a str>,
) -> Option<&'a str>

Why a record’s diff could not check its base: the refresh’s words when it ran, the store’s when the refresh answered nothing, and none when no refresh ran - the field names git’s words, never forge’s own.