error: Non-singleton `EncodeLabelSet` can only be derived on structs
 --> tests/ui/labels/unsupported_container.rs:4:1
  |
4 | enum Unsupported {}
  | ^^^^^^^^^^^^^^^^^^^

error: Encoded fields must be named
 --> tests/ui/labels/unsupported_container.rs:7:23
  |
7 | struct UnsupportedToo(u8);
  |                       ^^

error: `rename_all` attribute can only be placed on enums
  --> tests/ui/labels/unsupported_container.rs:10:1
   |
10 | / #[metrics(rename_all = "snake_case")]
11 | | struct UnsupportedForValue {
12 | |     test: u8,
13 | | }
   | |_^