can you provide a self contained reproducer?

cc @neelance @cherrymui

please find a repo where the case is reproductible
https://gitlab.com/c1560/cryptofiscafacile/-/tree/develop

It is a monorepo with a wasm lib and a frontend in Ember which use the wasm lib

Here is a much more simple example : https://github.com/fiscafacile/exampleGoWasmIssue49710

The Run button never get enabled, event after fetch(main.wasm) and Wasm Init is done ("Go WebAssembly Initialized" in Console)

I think this feature is working as intended. The promise returned by go.run resolves when the Wasm program exits. In the original example, the Wasm program is not intended to exit (because the host JS application will make calls into it).

If you want the host application to wait for the Wasm program to finish initializing, you can create a promise in the host application and resolve it from the Wasm program. For example, you might modify the code in the original post like this:

let isReady = new Promise((resolve) => {
  // @ts-ignore
  window.onWasmInitialized = resolve;
});

export async function loadCff2Wasm() {
  const go = new Go();
  const result = await WebAssembly.instantiateStreaming(fetch('cff2.wasm'), go.importObject);

  go.run(result.instance);
  await isReady;
}

You can then add the following call in the Go Wasm program after it is initialized:

js.Global().Get("onWasmInitialized").Invoke()

This call will resolve the isReady promise and let the host application continue.

You might also consider calling and awaiting go.run in a setTimeout so that you can perform some action if the Wasm program exits.

setTimeout(async () => {
  await go.run(result.instance);
  console.log('Wasm program exited! ...Restart it?');
});

Closing based on the last comment. Please comment if you disagree.