 --> [ local path prefix ]/state_machine/types/enum_undef_type.fpp:2:12
  |
2 |   enum E : T { X }
  |            ^ cannot find type `T` in scope

 --> [ local path prefix ]/state_machine/types/enum_undef_type.fpp:2:12
  |
2 |   enum E : T { X }
  |            ^ primitive integer type must be used

 --> [ local path prefix ]/state_machine/types/enum_undef_type.fpp:1:15
  |
1 | state machine SM {
  |               ^^ state machine must have initial transition

