Version

3.1.0-beta.2

Reproduction link

https://sfc.vuejs.org/#eyJBcHAudnVlIjoiPHRlbXBsYXRlPlxuICA8Q29tcCByZWY9XCJzb25SZWZcIi8+XHRcbiAgPGJ1dHRvbiBAY2xpY2s9XCJoYW5kbGVcIj5oYW5kbGU8L2J1dHRvbj5cbjwvdGVtcGxhdGU+XG5cbjxzY3JpcHQgc2V0dXA+XG5pbXBvcnQgeyByZWYgfSBmcm9tICd2dWUnXG5pbXBvcnQgQ29tcCBmcm9tICcuL0NvbXAudnVlJ1xuY29uc3Qgc29uUmVmID0gcmVmKG51bGwpXG5jb25zdCBoYW5kbGUgPSAoKSA9PiB7XG4gIGNvbnNvbGUubG9nKHNvblJlZi52YWx1ZSkgLy93aHkgZW1wdHkge30/XG4gIHNvblJlZi52YWx1ZS5jaGFuZ2UoJ2hlbGxvJykgLy9lcnJvclxufVxuPC9zY3JpcHQ+IiwiQ29tcC52dWUiOiI8dGVtcGxhdGU+XG4gIDxoMT57eyBtc2cgfX08L2gxPlxuPC90ZW1wbGF0ZT5cblxuPHNjcmlwdCBzZXR1cD5cbmltcG9ydCB7IHJlZiB9IGZyb20gJ3Z1ZSdcblxuY29uc3QgbXNnID0gcmVmKCdIZWxsbyBXb3JsZCEnKVxuY29uc3QgY2hhbmdlID0gKHZhbHVlKSA9PiB7XG4gICBtc2cudmFsdWUgPSB2YWx1ZVxufVxuPC9zY3JpcHQ+In0=

Steps to reproduce

When a child component uses Script Setup，I try to get the child instance through refs, I get an empty object

What is expected?

When a child component uses Script Setup, an instance of the child component can be obtained through refs

What is actually happening?

You can't get a child component instance when a child uses Script Setup, but you can get instance data when a child uses DefineComponent ({setUp (){}})

See https://github.com/vuejs/rfcs/blob/script-setup-2/active-rfcs/0000-script-setup.md#closed-by-default