derive-termination 2.0.0

Derive the std::process::Termination trait for an enum (annotate the variants with `#[exit_code(n)`).
Documentation 
1
2
3
4
5

error: Variant 'Missing' requires an #[exit_code(N)] attribute
 --> tests/ui/missing_attribute.rs:7:5
  |
7 |     Missing,
  |     ^^^^^^^