$ rustc -V
rustc 1.92.0-nightly (dd7fda570 2025-09-20)

$ cargo build
   Compiling devise_core v0.2.1
error[E0557]: feature has been removed
 --> /home/dereckson/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/devise_core-0.2.1/src/lib.rs:2:12
  |
2 | #![feature(concat_idents)]
  |            ^^^^^^^^^^^^^ feature has been removed
  |
  = note: removed in 1.90.0; see <https://github.com/rust-lang/rust/pull/142704> for more information
  = note: use the `${concat(..)}` metavariable expression instead

error: cannot find macro `concat_idents` in this scope
   --> /home/dereckson/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/devise_core-0.2.1/src/generator.rs:29:39
    |
 29 |               $(self.$vec.push(Box::new(concat_idents!(default_, $get_f)));)*
    |                                         ^^^^^^^^^^^^^
...
193 | /     mappers! {
194 | |         (map_struct, try_map_struct, struct_mapper): Struct, struct_mappers,
195 | |         (map_enum, try_map_enum, enum_mapper): Enum, enum_mappers,
196 | |         (map_variant, try_map_variant, variant_mapper): Variant, variant_mappers,
197 | |         (map_fields, try_map_fields, fields_mapper): Fields, fields_mappers,
198 | |         (map_field, try_map_field, field_mapper): Field, field_mappers
199 | |     }
    | |_____- in this macro invocation
    |
    = note: this error originates in the macro `mappers` (in Nightly builds, run with -Z macro-backtrace for more info)

For more information about this error, try `rustc --explain E0557`.
error: could not compile `devise_core` (lib) due to 2 previous errors