A function that returns a value in block throws an error

[ukyo]

A function that returns a value in block throws an error as below.

export function foo(x: int32): int32 {
  {
    return 100;
  }
}

fetch("foo.wasm")
.then(res => res.arrayBuffer())
.then(buff => WebAssembly.instantiate(buff))
.then(({module, instance}) => {
  console.log(instance.exports.foo(1));
});

(index):8 Uncaught (in promise) CompileError: Compiling WASM function #0:<?> failed:Result = expected 1 elements on the stack for fallthru to @1 @+8

wast code(generated with wasm2wast)

(module
  (type (;0;) (func (result i32)))
  (func (;0;) (type 0) (result i32)
    block  ;; label = @1
      i32.const 100
      return
    end)
  (memory (;0;) 1)
  (export "memory" (memory 0))
  (export "foo" (func 0))
  (data (i32.const 8) "\db\0fI@(\00\00\00(\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00"))

[nidin]

Its a known bug. A block should define a return type if something returned inside a block.