this derivation will be built:
  /nix/store/3myas682q7ljs16qbygr9xcz2pjmhd8j-iets-fmt-0.1.0.drv
error: Cannot build '/nix/store/3myas682q7ljs16qbygr9xcz2pjmhd8j-iets-fmt-0.1.0.drv'.
       Reason: builder failed with exit code 1.
       Output paths:
         /nix/store/ljbsck2gwclxp2mwj1h0k9w4zdv4zm3s-iets-fmt-0.1.0
       Last 25 log lines:
       > cargo 1.98.0 (797e8a9bc 2026-08-05)
       > +++ command cargo fmt -- --check
       > Diff in /build/source/src/parallel/fiber.rs:12:
       >  use std::sync::atomic::{AtomicU8, AtomicUsize, Ordering};
       >  use std::{error, io, mem, ptr};
       >
       > -use rustix::mm::{Advice, MapFlags, MprotectFlags, ProtFlags, madvise, mmap_anonymous, mprotect};
       >  use crate::runtime::heap;
       > +use rustix::mm::{Advice, MapFlags, MprotectFlags, ProtFlags, madvise, mmap_anonymous, mprotect};
       > 
       >  pub const DEFAULT_STACK: usize = 256 << 20;
       >  /// Stack of the demand fiber and of the process main thread. The demand
       > Diff in /build/source/src/parallel/interner.rs:9:
       >  use std::sync::{Arc, RwLock};
       >  use std::{process, ptr};
       >
       > -use rustix::mm::{MapFlags, ProtFlags, mmap_anonymous, munmap};
       >  use crate::runtime::heap::Heap;
       >  use crate::session::Session;
       >  use crate::syntax::symbol::{FxHasher, Sym};
       > Diff in /build/source/src/parallel/interner.rs:16:
       > +use rustix::mm::{MapFlags, ProtFlags, mmap_anonymous, munmap};
       > 
       >  const SHARDS: usize = 64;
       >
       For full logs, run:
         nix log /nix/store/3myas682q7ljs16qbygr9xcz2pjmhd8j-iets-fmt-0.1.0.drv