message: Fix id enum parsing
diff: @@ -68,7 +68,7 @@ macro_rules! id {
  fn from_str(s: &str) -> Result<Self, Self::Err> {
  let prefix = s.find('_')
  - .map(|i| &s[0..i])
  + .map(|i| &s[0..i+1])
  .ok_or_else(|| ParseIdError {
  typename: stringify!($enum_name),
  expected: "id to start with a prefix (as in 'prefix_')"
  