unstable `different-binary-name` is not compatible with `wasm32-unknown-emscripten`

[weihanglo]

Problem

For wasm32-unknown-emscripten target, the path of the .wasm file name is embedded in the output .js file. However, different-binary-name changes both file name of .wasm and .js when uplifting final binaries to target/debug directory, but not the .wasm path embedded in .js file.

Steps

1. Have a project enabling different-binary-name unstable feature

   cargo-features = ["different-binary-name"]
   
   [package]
   name = "a-b-c"
   version = "0.1.0"
   edition = "2021"
   [[bin]]
   name = "a-b-c"
   filename = "a-b-c_a_b_c"
   path = "src/main.rs"
   

2. nix-shell -p emscripten
3. rustup +nightly target add wasm32-unknown-emscripten
4. cargo +nightly build
5. ls target/wasm32-unknown-emscripten/debug/a-b-c_a_b_c.wasm and observe it exists
6. rg '\.wasm' target/wasm32-unknown-emscripten/debug/a-b-c_a_b_c.js and observe wasmBinaryFile = 'a_b_c.wasm'

Possible Solution(s)

Do not change name of the .wasm file for wasm32-unknown-emscripten.

Notes

No response

Version

cargo 1.77.0-nightly (7bb7b5395 2024-01-20)
release: 1.77.0-nightly
commit-hash: 7bb7b539558dc88bea44cee4168b6269bf8177b0
commit-date: 2024-01-20