It builds fine with EMSDK 3.1.43.

use std::{fs::File, io::Read}; fn main() { let mut file = File::open("Hello world!").unwrap(); let mut buf = Vec::new(); file.read_to_end(&mut buf); }

= note: wasm-ld: error: C:\Users\Przemyslaw.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\wasm32-unknown-emscripten\lib\libstd-330edb0856239641.rlib(std-330edb0856239641.std.fa9f9c7c191d43dc-cgu.0.rcgu.o): undefined symbol: open64
wasm-ld: error: C:\Users\Przemyslaw.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\wasm32-unknown-emscripten\lib\libstd-330edb0856239641.rlib(std-330edb0856239641.std.fa9f9c7c191d43dc-cgu.0.rcgu.o): undefined symbol: fstat64
wasm-ld: error: C:\Users\Przemyslaw.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\wasm32-unknown-emscripten\lib\libstd-330edb0856239641.rlib(std-330edb0856239641.std.fa9f9c7c191d43dc-cgu.0.rcgu.o): undefined symbol: lseek64

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rustc --version --verbose:

rustc 1.73.0 (cc66ad468 2023-10-03) binary: rustc commit-hash: cc66ad468955717ab92600c770da8c1601a4ff33 commit-date: 2023-10-03 host: x86_64-pc-windows-msvc release: 1.73.0 LLVM version: 17.0.2 

<backtrace>