emscripten-sys-0.2.0 has been yanked.
Emscripten API bindings for Rust
How to build
. <path to emsdk>/emsdk_env.sh
cargo build
How to test
cargo test --target asmjs-unknown-emscripten --no-run
node target/asmjs-unknown-emscripten/debug/emscripten_sys-*.js