Build Failed: use of unstable library feature 'array_from_fn'

[yuquan1210]

Summary of Bug

error[E0658]: use of unstable library feature 'array_from_fn'
   --> /root/.cargo/git/checkouts/algebra-7e23afa68841b66e/d3e888d/serialize/src/impls.rs:415:22
    |
415 |         let result = core::array::from_fn(|_| {
    |                      ^^^^^^^^^^^^^^^^^^^^
    |
    = note: see issue #89379 <https://github.com/rust-lang/rust/issues/89379> for more information

For more information about this error, try `rustc --explain E0658`.
error: could not compile `ark-serialize` due to previous error
warning: build failed, waiting for other jobs to finish...
error: build failed

Version

commit f6df807
Update ark-snark to ark-algebra (#366)

Steps to Reproduce

Run build with cargo build --release

Please suggestion a solution for this issue as I am new to Rust and Arkworks. Thank you!

[Pratyush]

Hi! The error is probably because we've updated the library to use features from a newer (but still stable) version of Rust. If using rustup, I would run rustup update to get the latest stable version of Rust, and this problem should go away.

[yuquan1210]

My rust should be the latest version, and the problem is still there. Do you have another fix?

info: syncing channel updates for 'stable-x86_64-unknown-linux-gnu'
info: checking for self-updates

  stable-x86_64-unknown-linux-gnu unchanged - rustc 1.64.0 (a55dd71d5 2022-09-19)

info: cleaning up downloads & tmp directories

[Pratyush]

Hm can you run rustc --version in your repo? The array_from_fn method is stable as of 1.63: https://doc.rust-lang.org/std/array/fn.from_fn.html

[yuquan1210]

rustc 1.64.0 (a55dd71d5 2022-09-19). This is the output, and the error showed it is actually using array::from_fn. Is it the same as array_from_fn?

[Pratyush]

Sorry, I meant the array_from_fn feature was partially stabilized; this stabilization enables the use of array::from_fn on stable.