these 2 derivations will be built:
  /nix/store/6dr2ls6mkhhycdfwzj4gxlmdpbm44bgh-cargo-vendor-dir.drv
  /nix/store/vs32aaw04r20xirfj37028d8f1ps2hrh-peephole-0.1.0.drv
error: Cannot build '/nix/store/vs32aaw04r20xirfj37028d8f1ps2hrh-peephole-0.1.0.drv'.
       Reason: builder failed with exit code 101.
       Output paths:
         /nix/store/rz2fix3q57ipc6hh53wlliqclyfwjki3-peephole-0.1.0
       Last 25 log lines:
       > 71 -             && sig.unsafety.is_none()
       > 71 +             && sig.safety.is_none()
       >    |
       >
       > error[E0609]: no field `reference` on type `&syn::Receiver`
       >    --> macros/src/lib.rs:108:47
       >     |
       > 108 |                 let access = match (&receiver.reference, receiver.mutability) {
       >     |                                               ^^^^^^^^^ unknown field
       >     |
       >     = note: available fields are: `attrs`, `mutability`, `self_token`, `kind`
       >
       > error[E0609]: no field `guard` on type `&mut Arm`
       >    --> macros/src/lib.rs:365:60
       >     |
       > 365 |                         if let Some((_, guard)) = &mut arm.guard {
       >     |                                                            ^^^^^ unknown field
       >     |
       >     = note: available fields are: `attrs`, `pat`, `fat_arrow_token`, `body`, `comma`
       >
       > Some errors have detailed explanations: E0308, E0609.
       > For more information about an error, try `rustc --explain E0308`.
       > error: could not compile `peephole-macros` (lib) due to 4 previous errors
       > warning: build failed, waiting for other jobs to finish...
       > error: could not compile `peephole-macros` (lib) due to 4 previous errors
       For full logs, run:
         nix log /nix/store/vs32aaw04r20xirfj37028d8f1ps2hrh-peephole-0.1.0.drv