error: elided lifetime has a name
  --> src/failure.rs:27:39
   |
27 |     fn source<'a>(&'a self) -> Option<&(dyn error::Error + 'static)> {
   |               --                      ^ this elided lifetime gets resolved as `'a`
   |               |
   |               lifetime `'a` declared here
   |
   = note: `-D elided-named-lifetimes` implied by `-D warnings`
   = help: to override `-D warnings` add `#[allow(elided_named_lifetimes)]`