An error: Non-sendable type 'Realm' returned by implicitly asynchronous call to nonisolated function cannot cross actor boundary with Swift6

[qihuijia]

How frequently does the bug occur?

Always

Description

I just follow use-realm-with-actors document, and add this code in Xcode 16.1, Swift 6 in my package.

actor RealmActor {
    // An implicitly-unwrapped optional is used here to let us pass `self` to
    // `Realm(actor:)` within `init`
    var realm: Realm!
    init() async throws {
        realm = try await Realm(actor: self)
    }
}

and then there is a error: Non-sendable type 'Realm' returned by implicitly asynchronous call to nonisolated function cannot cross actor boundary.

And my package settings is like this:

// swift-tools-version: 6.0

import PackageDescription

let package = Package(
    name: "XXX",
    platforms: [
        .iOS(.v18)
    ],
    ...
    targets: [
            .target(
                name: "XXX",
                dependencies: [
                    .product(name: "RealmSwift", package: "realm-swift")
                ],
                swiftSettings: [
                    .swiftLanguageMode(.v6)
                ]
            ),
            .testTarget(
                name: "XXXTests",
                dependencies: ["XXX"]
            )
        ]

Stacktrace & log output

no. this is the compile error.

Can you reproduce the bug?

Always

Reproduction Steps

No response

Version

20.0.1

What Atlas Services are you using?

Local Database only

Are you using encryption?

No

Platform OS and version(s)

iOS 18.0

Build environment

Xcode version: 16.1