 --> [ local path prefix ]/state_machine/types/struct_undef_type.fpp:2:17
  |
2 |   struct S { x: T }
  |                 ^ cannot find type `T` in scope

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

