`cargo component new` in Workspace no longer works (`wit-bindgen` v`0.19.1`) about cargo-component

[peterhuene]

The problem is that cargo component new currently runs cargo add for the wit-bindgen dependency, and doing so with a workspace.dependencies entry causes a conflict due to --no-default-features being passed to cargo add (it can't be specified on the package dependency even if they're the same value, unfortunately).

To fix this, cargo component new will need to detect that a compatible workspace dependency already exists and use that instead.

To work around this, you'll need to temporarily remove the workspace dep, add the project, add the workspace dep back, and then convert the package dep to use the workspace one.

Also note that the current release of cargo-component isn't fully compatible with wit-bindgen 0.19.x; you may run into build errors, especially if you're using resources; what's in main currently works with it, and with #240 merged soon, I will probably cut a release of cargo-component.

[peterhuene]

Also note that we hope to remove the wit-bindgen dependency from user projects in the future, with work already done to prevent the kind of breakage that 0.19.x introduced; at a minimum, we might have a dependency on a tiny "canonical exports" crate that can be built without having to muck with features.

[peterhuene]

I verified that with these changes we get the expected behavior of cargo component new inside of a workspace where the dependencies are already specified:

[dependencies]
bitflags.workspace = true
wit-bindgen-rt.workspace = true

[DougAnderson444]

@benwis perhaps you're seeing workspace issues too?

[peterhuene]

With bytecodealliance/wit-bindgen#876 and the new wit-bindgen-rt crate published in the near future, cargo-component projects will then have only direct dependencies on bitflags (for the generated bindings) and wit-bindgen-rt (for exporting required canonical ABI functions).

And since this gets rid of having to specify features on the dependencies, it should help fix this particular issue!

[DougAnderson444]

@peterhuene you rock!