4 | struct Error;
  | -------------
  | |
  | doesn't satisfy `Error: anyhow::kind::TraitKind`
  | doesn't satisfy `Error: std::convert::Into<anyhow::Error>`
  | doesn't satisfy `Error: std::fmt::Display`
...

          `&Error : anyhow::kind::AdhocKind`
          `&Error : anyhow::kind::TraitKind`
          `Error : anyhow::kind::TraitKind`
  = help: items from traits can only be used if the trait is implemented and in scope
  = note: the following traits define an item `anyhow_kind`, perhaps you need to implement one of them:
          candidate #1: `anyhow::kind::AdhocKind`
          candidate #2: `anyhow::kind::TraitKind`
          candidate #3: `anyhow::kind::BoxedKind`

          `Error: std::convert::Into<anyhow::Error>`
          which is required by `Error: anyhow::kind::TraitKind`
          `Error: std::fmt::Display`
          which is required by `&Error: anyhow::kind::AdhocKind`
          `&Error: std::convert::Into<anyhow::Error>`
          which is required by `&Error: anyhow::kind::TraitKind`