error: `#[derive(From)]` used on a struct with no fields
  --> $DIR/deriving-from-wrong-target.rs:8:10
   |
LL | #[derive(From)]
   |          ^^^^
LL |
LL | struct S1;
   |        ^^
   |
   = note: `#[derive(From)]` can only be used on structs with exactly one field

error: `#[derive(From)]` used on a struct with no fields
  --> $DIR/deriving-from-wrong-target.rs:12:10
   |
LL | #[derive(From)]
   |          ^^^^
LL |
LL | struct S2 {}
   |        ^^
   |
   = note: `#[derive(From)]` can only be used on structs with exactly one field

error: `#[derive(From)]` used on a struct with multiple fields
  --> $DIR/deriving-from-wrong-target.rs:16:10
   |
LL | #[derive(From)]
   |          ^^^^
LL |
LL | struct S3(u32, bool);
   |        ^^
   |
   = note: `#[derive(From)]` can only be used on structs with exactly one field

error: `#[derive(From)]` used on a struct with multiple fields
  --> $DIR/deriving-from-wrong-target.rs:20:10
   |
LL | #[derive(From)]
   |          ^^^^
LL |
LL | struct S4 {
   |        ^^
   |
   = note: `#[derive(From)]` can only be used on structs with exactly one field

error: `#[derive(From)]` used on an enum
  --> $DIR/deriving-from-wrong-target.rs:27:10
   |
LL | #[derive(From)]
   |          ^^^^
LL |
LL | enum E1 {}
   |      ^^
   |
   = note: `#[derive(From)]` can only be used on structs with exactly one field

error[E0277]: the size for values of type `T` cannot be known at compilation time
  --> $DIR/deriving-from-wrong-target.rs:33:11
   |
LL | struct SUnsizedField<T: ?Sized> {
   |                      - this type parameter needs to be `Sized`
LL |     last: T,
   |           ^ doesn't have a size known at compile-time
   |
   = help: unsized fn params are gated as an unstable feature
help: consider removing the `?Sized` bound to make the type parameter `Sized`
   |
LL - struct SUnsizedField<T: ?Sized> {
LL + struct SUnsizedField<T> {
   |
help: function arguments must have a statically known size, borrowed types always have a known size
   |
LL |     last: &T,
   |           +

error: aborting due to 6 previous errors

For more information about this error, try `rustc --explain E0277`.