(Linux) Build failure against 2024-09-25 nightly toolchain -- error: cannot inherit from class 'Thread' (compiled with Swift 6.1) because it has overridable members that could not be loaded in Swift 5.10

[clackary]

This one is another instance of a swiftlang compiler bug I've been running into for a while: swiftlang/swift-corelibs-foundation#5108

root@7481e59c0960:/project/opentelemetry-swift# /home/dev-toolchain/swift-DEVELOPMENT-SNAPSHOT-2024-09-25-a-ubuntu22.04-aarch64/usr/bin/swift build
...
/project/opentelemetry-swift/Sources/OpenTelemetrySdk/Logs/Processors/BatchLogRecordProcessor.swift:41:15: error: cannot inherit from class 'Thread' (compiled with Swift 6.1) because it has overridable members that could not be loaded in Swift 5.10
 39 | }
 40 | 
 41 | private class BatchWorker : Thread {
    |               `- error: cannot inherit from class 'Thread' (compiled with Swift 6.1) because it has overridable members that could not be loaded in Swift 5.10
 42 |   let logRecordExporter : LogRecordExporter
 43 |   let scheduleDelay : TimeInterval

From what I've seen in the other cases, it looks like would be feasible to workaround the issue by making a Thread property within BatchWorker, and then wrapping the start and cancel calls with matching BatchWorker funcs.

But the problem here is the override on Thread.main(). I don't think there's a way to do this without inheriting from Thread.

Configuration:
OS: Linux Ubuntu 22.04
Toolchain: swift-DEVELOPMENT-SNAPSHOT-2024-09-25-a-ubuntu22.04-aarch64

[ArielDemarco]

Hey @clackary! You're right that it was introduced in that nightly build; and looking at the issue you created in swift-corelibs-foundation, it seems it's not expected (and thankfully, because it'd be quite problematic 😂). From what I see, they've opened a PR that theoretically solves the problem with both NSLock and Thread.
Maybe once that PR gets merged, it would be good to test and see if the problem disappears in the BatchWorker class