 --> [ local path prefix ]/state_machine/types/enum_default_error.fpp:2:27
  |
2 |   enum E { X, Y } default "abc"
  |                           ^^^^^ default value cannot be converted to E
  |
  = note: string cannot be converted to E

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

