Xcode not trapping asserts

Question

Created Jul ’20

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I am new to Xcode, so my apologies if there's a simple answer I've missed.

I converted an existing project, built using Swift and Objective C from Swift 3 to Swift 5 under Xcode 11.6 . When I run under the debugger, I am seeing a series of assert fails:

Cannot be called with asCopy = NO on non-main thread.

I understand that this means that UI calls are being made from background threads, but I don't know where the asserts are coming from. Everything I can find online implies that Xcode should stop on an assert fail, but it's not doing so.

I am building for Run with Build Configuration Debug. Debug executable is checked. I have created an Exception breakpoint which shows as All Objective-C Exceptions. I have turned on Main Thread Checker. Yet, I see the asserts logged, but Xcode doesn't stop.

Is there a way to make Xcode break on these assert fails? If not, what is the best method to find where they are happening. I had thought that Main Thread Checker should have tripped on them as well.

Thanks in advance

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Answer 1

DTS Engineer OP

Apple

Jul ’20

Add a Runtime Issue breakpoint though the Breakpoint Navigator. It can be configured to stop on all runtime issues, or just a particular set, such as those from the Main Thread Checker.

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Answer 2

Dharma OP

Jul ’20

That sounds like it might be useful, however, I'm not finding a way to do it. I'm using Xcode 11.6 . The Breakpoint Navigator only works on existing breakpoints, it does not allow adding any. Going to Debug\Breakpoints, I can add breakpoints, but the options are :
Add Breakpoint at Current Line
Create Swift Error Breakpoint (did this one)
Create Exception Breakpoint (did this one)
Create Symbolic Breakpoint
Create Test Failure Breakpoint (did this one)

None of these is breaking on the assert. I can't find a way to create a breakpoint that has the option to create a Runtime Issue Breakpoint

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