But now there comes another issue: this hello-world example is just too specific to wasi:cli, since we used a specific wasmtime_wasi::bindings::sync::Command to run a wasi:cli/command. For a more general component, we need to add another example or at least give a pointer.

BTW, I still don't know why I could not get a Func to execute the run function in wasi:cli/run.

Personally I think it's reasonable to start with hello-world like this and then graduate up to other examples. For example this page could link to the bindgen_examples page and that could get expanded with a custom world for example (IIRC there may already be one there?)

BTW, I still don't know why I could not get a Func to execute the run function in wasi:cli/run.

You needed another invocation of get_export. You loaded the exported instance but you'll need to load the exported function of that instance as well.

OK, I think this draft PR seems good to me now, so I turned it into a formal PR.

You needed another invocation of get_export. You loaded the exported instance but you'll need to load the exported function of that instance as well.

OK, got that. I also added related code in the example to demonstrate how to do that.

BTW, do you know why ComponentNamedList is implemented for tuple (A1,) but not A1? Should I file another issue for this? This is bit counter-intuitive when I want to write something like func.typed::<(), Result<(), ()>>(&store), which rustc complains about not implementing ComponentNamedList. I really didn't know how to fix this error until I lookup Implementations on Foreign Types section of ComponentNamedList.

Oops. CI complains about file not found target/wasm32-wasip2/debug/wasi.wasm, so I guess CMakeLists also needs to be updated.

Furthermore, I digged into examples/wasi/main.c and related c-api crate. It seems c-api crate also needs some renovation.........

For example, c-api exposes this function, which links wasip1 interfaces, but no other functions link wasip2 interfaces.

I think removing preview1 feature from this line and fixing whatever breaks should be enough. This introduces API breaking changes, though.

I'd rather like to skip this error first and open another tracking issue.

Can you take a look at the CI error Test C-API macos-latest? I think I made a right correction on CMakeList.txt but I don't know what else needs to be fixed.

Have you tried running the example locally?