warning: unexpected `cfg` condition name: `async_trait_nightly_testing`
     --> tests/test.rs:2:5
      |
    2 |     async_trait_nightly_testing,
      |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
      |
      = help: expected names are: `clippy`, `debug_assertions`, `doc`, `docsrs`, `doctest`, `feature`, `miri`, `overflow_checks`, `panic`, `proc_macro`, `relocation_model`, `sanitize`, `sanitizer_cfi_generalize_pointers`, `sanitizer_cfi_normalize_integers`, `target_abi`, `target_arch`, `target_endian`, `target_env`, `target_family`, `target_feature`, `target_has_atomic`, `target_has_atomic_equal_alignment`, `target_has_atomic_load_store`, `target_os`, `target_pointer_width`, `target_thread_local`, `target_vendor`, `test`, `ub_checks`, `unix`, `windows`
      = help: consider using a Cargo feature instead or adding `println!("cargo::rustc-check-cfg=cfg(async_trait_nightly_testing)");` to the top of the `build.rs`
      = note: see <https://doc.rust-lang.org/nightly/cargo/reference/build-scripts.html#rustc-check-cfg> for more information about checking conditional configuration
      = note: `#[warn(unexpected_cfgs)]` on by default

    warning: unexpected `cfg` condition name: `async_trait_nightly_testing`
       --> tests/test.rs:380:7
        |
    380 | #[cfg(async_trait_nightly_testing)]
        |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^
        |
        = help: consider using a Cargo feature instead or adding `println!("cargo::rustc-check-cfg=cfg(async_trait_nightly_testing)");` to the top of the `build.rs`
        = note: see <https://doc.rust-lang.org/nightly/cargo/reference/build-scripts.html#rustc-check-cfg> for more information about checking conditional configuration

    warning: unexpected `cfg` condition name: `async_trait_nightly_testing`
        --> tests/test.rs:1298:7
         |
    1298 | #[cfg(async_trait_nightly_testing)]
         |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^
         |
         = help: consider using a Cargo feature instead or adding `println!("cargo::rustc-check-cfg=cfg(async_trait_nightly_testing)");` to the top of the `build.rs`
         = note: see <https://doc.rust-lang.org/nightly/cargo/reference/build-scripts.html#rustc-check-cfg> for more information about checking conditional configuration

    warning: unexpected `cfg` condition name: `async_trait_nightly_testing`
        --> tests/test.rs:1627:7
         |
    1627 | #[cfg(async_trait_nightly_testing)]
         |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^
         |
         = help: consider using a Cargo feature instead or adding `println!("cargo::rustc-check-cfg=cfg(async_trait_nightly_testing)");` to the top of the `build.rs`
         = note: see <https://doc.rust-lang.org/nightly/cargo/reference/build-scripts.html#rustc-check-cfg> for more information about checking conditional configuration

Resolve unexpected_cfgs warning

Since nightly-2024-06-05.

    warning: unknown lint: `where_clauses_object_safety`
        --> tests/test.rs:1383:8
         |
    1383 | #[deny(where_clauses_object_safety)]
         |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^
         |
         = note: `#[warn(unknown_lints)]` on by default

Former where_clauses_object_safety lint is now hard error

    warning: struct `Struct` is never constructed
       --> tests/test.rs:338:16
        |
    338 |     pub struct Struct {
        |                ^^^^^^
        |
        = note: `#[warn(dead_code)]` on by default

and default too

syn: remove derive feature

When syn/clone-impls isn't enabled, this type is not Copy.

    warning: this argument (4 byte) is passed by reference, but would be more efficient if passed by value (limit: 8 byte)
      --> src/lifetime.rs:22:49
       |
    22 |     fn visit_opt_lifetime(&mut self, reference: &Token![&], lifetime: &mut Option<Lifetime>) {
       |                                                 ^^^^^^^^^^ help: consider passing by value instead: `$crate::token::And`
       |
       = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#trivially_copy_pass_by_ref
       = note: `-W clippy::trivially-copy-pass-by-ref` implied by `-W clippy::pedantic`
       = help: to override `-W clippy::pedantic` add `#[allow(clippy::trivially_copy_pass_by_ref)]`

Turn off syn/clone-impls feature