[SR-15282] Using an actor with NSObject conformance on Linux

[mickeyl]

Previous ID	SR-15282
Radar	rdar://problem/83878042
Original Reporter	@mickeyl
Type	Bug

Environment

Swift 5.5, Linux.

Additional Detail from JIRA

Votes	0
Component/s	Foundation
Labels	Bug, Concurrency
Assignee	None
Priority	Medium

md5: 75d39d970ff122b78002957b1976920f

Issue Description:

I have a {{public actor StreamCommandQueue: NSObject }}, which implements StreamDelegate, hence I have to derive from NSObject.

On Apple platforms, that works fine. On Linux I get the error:

error: actor-isolated initializer 'init()' has different actor isolation from nonisolated overridden declarationpublic actor StreamCommandQueue: NSObject { Foundation.NSObject:2:12: note: overridden declaration is here public init()

Why the difference and how am I supposed to fix that?

[ktoso]

Thanks for reporting, we'll have a look - at first look it seems it might be a bug, initializers are not really intended to be isolated.

You could try overriding with `nonisolated init()` as workaround ?

@swift-ci create

[mickeyl]

@ktoso Unfortunately that doesn't work:

error: nonisolated initializer 'init()' has different actor isolation from nonisolated overridden declaration
 override nonisolated init() {
 ^
Foundation.NSObject:2:12: note: overridden declaration is here
 public init()