Build failing with cargo +nightly

[Pancf]

I encountered errors like that

error[E0658]: use of unstable library feature 'array_value_iter'
--> /Users/Pancf/.cargo/registry/src/github.com-1ecc6299db9ec823/rustc-ap-rustc_arena-702.0.0/src/lib.rs:134:40
|
134 | impl<T, const N: usize> IterExt for std::array::IntoIter<T, N> {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: see issue #65798 rust-lang/rust#65798 for more information
= help: add #![feature(array_value_iter)] to the crate attributes to enable
error[E0658]: use of unstable library feature 'array_value_iter_slice'
--> /Users/Pancf/.cargo/registry/src/github.com-1ecc6299db9ec823/rustc-ap-rustc_arena-702.0.0/src/lib.rs:144:18
|
144 | self.as_slice().as_ptr().copy_to_nonoverlapping(start_ptr, len);
| ^^^^^^^^
|
= note: see issue #65798 rust-lang/rust#65798 for more information
= help: add #![feature(array_value_iter_slice)] to the crate attributes to enable
error: aborting due to 2 previous errors
For more information about this error, try rustc --explain E0658.
error: could not compile rustc-ap-rustc_arena
To learn more, run the command again with --verbose.
warning: build failed, waiting for other jobs to finish...
error: build failed

Env:
macOS
rustup 1.23.1 (3df2264a9 2020-11-30)
rustc 1.49.0 (e1884a8e3 2020-12-29)
rustc 1.51.0-nightly (04caa632d 2021-01-30)
cargo 1.49.0 (d00d64df9 2020-12-05)
cargo 1.51.0-nightly (c3abcfe8a 2021-01-25)

[calebcartwright]

Fixed in #1153, though you'll need a newer nightly (use --force with rustup update)

[look]

Thanks, I just ran into this too and running rustup update --force nightly and then re-running cargo +nightly install racer fixed it for me. 🙇