When I was experimenting WASM with rust, I accidentally found that even very little function was used, the whole
std crate seems being included in the final WASM binary, which bloats the final binary about 600 KB. In my experiment, I just wrote a simple crc32.
I already have a temporary work-around for this by manually use
no_std, which follows instructions on official document.
I’m not familiar with Rust yet and not sure about posting this here, but I think someone may interested in this issue.