❯ cargo build
warning: no edition set: defaulting to the 2015 edition while 2018 is compatible with `rust-version`
   Compiling shlex v1.3.0 (.../rust-shlex)
warning: unexpected `cfg` condition name: `manual_codegen_check`
   --> src/bytes.rs:353:12
    |
353 | #[cfg_attr(manual_codegen_check, inline(never))]
    |            ^^^^^^^^^^^^^^^^^^^^
    |
    = help: expected names are: `clippy`, `debug_assertions`, `doc`, `docsrs`, `doctest`, `feature`, `fmt_debug`, `miri`, `overflow_checks`, `panic`, `proc_macro`, `relocation_model`, `rustfmt`, `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`, and `windows`
    = help: consider using a Cargo feature instead
    = help: or consider adding in `Cargo.toml` the `check-cfg` lint config for the lint:
             [lints.rust]
             unexpected_cfgs = { level = "warn", check-cfg = ['cfg(manual_codegen_check)'] }
    = help: or consider adding `println!("cargo::rustc-check-cfg=cfg(manual_codegen_check)");` to the top of the `build.rs`
    = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
    = note: `#[warn(unexpected_cfgs)]` on by default

warning: `shlex` (lib) generated 1 warning
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.09s