 --> [ local path prefix ]/state_machine/types/struct_default_error.fpp:5:13
  |
5 |     default { x = 0, e = E.X, a = [ 1, 2, 3 ], b = 5 }
  |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ default value cannot be converted to S
  |
  = note: struct missing member `b`

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

