The wasm-rust.md example with interface types does not work.

[tiptop96]

https://github.com/bytecodealliance/wasmtime/blob/master/docs/wasm-rust.md#webassembly-interface-types

Problem number one is that it will not work with a higher version thanwasm-bindgen = "=0.2.55". Currently it is set to wasm-bindgen = "0.2.54" which will install a higher minor version than 55. This has been discussed, see: bytecodealliance/wasmtime-demos#13 (comment)

The second is that the wasmtime command requires the --enable-multi-value flag when using interface types (maybee this is just specific to the way the wasm-bindgen proc-macro works?). Or we get this.

$ wasmtime --invoke greet target/wasm32-wasi/release/wasm_greeting.wasm "Wooo!"
Error: failed to run main module `target/wasm32-wasi/release/wasm_greeting.wasm`

Caused by:
    invalid result arity: func type returns multiple values (at offset 43)

I have a PR ready to fix these, unless anyone has anything to add?

[tiptop96]

@alexcrichton I can't assign you but I think you'd be the best person too look at this, being the author of the linked comment.

[alexcrichton]

Thanks for the report!

Unfortunately at this time the demos of interface types are broken and we haven't gotten around to discussing how best to update documentation and update the state of the world. There's some discussion on Zulip though if you're curious to jump in!

[alexcrichton]

I'm going to now that we've temporarily removed interface types support, but stay tuned to #677 for future updates!