error: transparent error struct can't contain #[source]
 --> tests/ui/transparent-struct-source.rs:5:18
  |
3 | #[derive(Error, Debug)]
  |          ----- in this derive macro expansion
4 | #[error(transparent)]
5 | pub struct Error(#[source] anyhow::Error);
  |                  ^^^^^^^^^
  |
  = note: this error originates in the derive macro `Error` (in Nightly builds, run with -Z macro-backtrace for more info)