SIGSEGV in withTaskCancellationHandler(operation:onCancel:isolation:)

[setoelkahfi]

Description

Hello, we have started migrating our codebase to Swift 6 language mode and fully migrated our TCA to be concurrency-ready for quite some time now. We updated our Xcode 16 and started seeing this crash on tvOS 18:

Project
+0xd4f76c
$ss27withTaskCancellationHandler9operation8onCancel9isolationxxyYaKXE_yyYbXEScA_pSgYitYaKlFTwbyt_Tg5 (<compiler-generated>)
In App

Project
+0xd4f76c
closure in RootStore.send (RootStore.swift:135)
In App

Called from
libswift_Concurrency
+0x042150
swift::runJobInEstablishedExecutorContext

Any clue?

Checklist

• I have determined whether this bug is also reproducible in a vanilla SwiftUI project.
• If possible, I've reproduced the issue using the main branch of this package.
• This issue hasn't been addressed in an existing GitHub issue or discussion.

Expected behavior

No crash.

Actual behavior

No response

Reproducing project

No response

The Composable Architecture version information

1.15

Destination operating system

tvOS 18 and up.

Xcode version information

Xcode 16

Swift Compiler version information

swift-driver version: 1.115 Apple Swift version 6.0 (swiftlang-6.0.0.9.10 clang-1600.0.26.2)
Target: arm64-apple-macosx14.0

[mbrandonw]

Hi @setoelkahfi, unfortunately there is not enough information here to be of any help. At the very least a more complete stack trace would help, but ideally you would be able to provide a minimal project that demonstrates the crash. Can you try to do that as it helps us a lot and almost always leads to a resolution of the problem.

Since it isn't clear that this is an issue with the library I am going to convert it to a discussion. Please feel free to continue the conversation over there!

[jshier]

There are multiple crashes in the global with* functions right now, depending on OS and Xcode version. https://forums.swift.org/t/global-with-concurrency-functions-crash-on-catalyst-designed-for-ipad-on-macos/74823/1 Update to Xcode 16.1 and some may be fixed.

[setoelkahfi]

Updating the project to Xcode 16.1 fixes the issue.