type annotations needed in libp2p-noise

Question

On cargo build --release in my substrate project I am getting

error[E0282]: type annotations needed
   --> /home/asmita-mfs/.cargo/registry/src/github.com-1ecc6299db9ec823/libp2p-noise-0.32.0/src/protocol/x25519.rs:221:45
    |
221 |         curve25519_sk.copy_from_slice(&hash.as_ref()[..32]);
    |                                        -----^^^^^^--
    |                                        |    |
    |                                        |    cannot infer type for type parameter `T` declared on the trait `AsRef`
    |                                        this method call resolves to `&T`
    |
    = note: type must be known at this point

For more information about this error, try `rustc --explain E0282`.
error: could not compile `libp2p-noise` due to previous error

What can be the reason for the above error. The above error is coming when I tried to integrate eth-light-client pallet in my substrate project created from monthly-2021-09+1 tag
https://github.com/webb-tools/substrate-eth-light-client/tree/drew/update-to-recent-substrate/pallets/light-client

Answer 1

I'd make sure you're using a nightly from at least 2021-09-1. It's probably just that you're using an earlier compiler that was not as clever. In general using a nightly from near the tag is likely to be a good call.