these 4 derivations will be built:
  /nix/store/caxb5qrklj5sn3mm93qqpi7dd47sfm1w-Cargo.toml.drv
  /nix/store/ysbidzxz0wf3293id6rfwz9izxijckcp-source.drv
  /nix/store/6jsxdfv8wmydkzrhbz5inw8gm37qamkl-herdr-eternal-deps-0.1.0.drv
  /nix/store/a08s1qgnvjzam12abinlbypav7kx7a96-herdr-eternal-0.1.0.drv
error: Cannot build '/nix/store/a08s1qgnvjzam12abinlbypav7kx7a96-herdr-eternal-0.1.0.drv'.
       Reason: builder failed with exit code 101.
       Output paths:
         /nix/store/7gcx125sbz2x31hsh6s1w57xwl2d65mk-herdr-eternal-0.1.0
       Last 25 log lines:
       >    |                                    ^^^^^^^^ unknown field
       >    |
       >    = note: available fields are: `cert`, `signing_key`
       >
       > For more information about this error, try `rustc --explain E0609`.
       > error: could not compile `herdr-eternal-ssh` (test "quic") due to 1 previous error
       > warning: build failed, waiting for other jobs to finish...
       > error[E0609]: no field `key_pair` on type `CertifiedKey<KeyPair>`
       >    --> client/examples/latency.rs:118:36
       >     |
       > 118 |     std::fs::write(&key_path, cert.key_pair.serialize_pem()).unwrap();
       >     |                                    ^^^^^^^^ unknown field
       >     |
       >     = note: available fields are: `cert`, `signing_key`
       >
       > error: could not compile `herdr-eternal-ssh` (example "latency") due to 1 previous error
       > error[E0609]: no field `key_pair` on type `rcgen::CertifiedKey<rcgen::KeyPair>`
       >    --> client/src/channel.rs:232:67
       >     |
       > 232 |         let key = rustls_pki_types::PrivatePkcs8KeyDer::from(cert.key_pair.serialize_der());
       >     |                                                                   ^^^^^^^^ unknown field
       >     |
       >     = note: available fields are: `cert`, `signing_key`
       >
       > error: could not compile `herdr-eternal-ssh` (lib test) due to 1 previous error
       For full logs, run:
         nix log /nix/store/a08s1qgnvjzam12abinlbypav7kx7a96-herdr-eternal-0.1.0.drv