Compile errors

[OS-Michael]

unknown feature proc_macro_span_shrink
and
#![cfg_attr(feature = "stdsimd", feature(stdsimd))]

I did "cargo build" Nothing specific

[MommaWatasu]

I'm sorry but I can't guess what causes that error since I haven't maintained this repo for long. But one thing I can say is that the error means the crate(bevy) has changed greatly and my code is no longer valid.
I strongly suggest you look at the document of bevy for yourself. It seems that bevy gets much stronger than before.

[OS-Michael]

I think that It didn't compile, because the crate "ahash-0.7.6" and crate "proc-macro2-1.0.46" just don't work anymore. I guess they are not updated on crates.io. It could also be because of the Rust version, I use 2021 (or try to).