request: Support multiple package in a single WIT

[Mossaka]

relevent upstream work:

bytecodealliance/wasm-tools#1577
bytecodealliance/wit-bindgen#978

It seems like the latest research of cargo-component does not support multi-packages in WITs.

Caused by:
    0: failed to parse local target from directory `/Users/mossaka/Developer/mossaka/hello-component-wasi-http-part2/wit`
    1: expected ';', found '{'
            --> /Users/mossaka/Developer/mossaka/hello-component-wasi-http-part2/wit/wasi_http.wit:1:23
             |
           1 | package wasi:[email protected] {
             |                       ^
(base) ➜  hello-component-wasi-http-part2 

[kate-goldenring]

I am happy to take a look at this

[macovedj]

Also happy to help out with this. I helped a bit with some of the more recent changes for multi-package WIT stuff. I wouldn't be surprised if there are additional changes that need to be made in wit-bindgen.

[macovedj]

Also looking again, I'm curious if the example was written before or after this change. It looks like this example may not have a root package declaration, which is required after the linked change.

[kate-goldenring]

It may have been from before; however, even with the root package declaration, cargo component fails to compile the app, in part because it assumes the name of each dependency is that of the package group's root package:

cargo-component/crates/core/src/registry.rs

Line 387 in faf251f

pub fn package_name(&self) -> &PackageName {

error: failed to create a target world for package `baz` (/Users/kagold/Programs/cargo-component/_scratch/baz/Cargo.toml)

Caused by:
    duplicate definitions of package `root:root` found while decoding target dependency `bar:baz`