App crashing with SIGABRT in `once.h` on definition of `dispatch_once`

Question

I'm suddenly getting a SIGABRT in dispatch_once as shown in Xcode below.

No changes have been recently added that use dispatch_once.

dispatch_once(predicate, block); Thread 1: signal SIGABRT

#if DISPATCH_ONCE_INLINE_FASTPATH
DISPATCH_INLINE DISPATCH_ALWAYS_INLINE DISPATCH_NONNULL_ALL DISPATCH_NOTHROW
DISPATCH_SWIFT3_UNAVAILABLE("Use lazily initialized globals instead")
void
_dispatch_once(dispatch_once_t *predicate,
        DISPATCH_NOESCAPE dispatch_block_t block)
{
    if (DISPATCH_EXPECT(*predicate, ~0l) != ~0l) {
        dispatch_once(predicate, block);
    } else {
        dispatch_compiler_barrier();
    }
    DISPATCH_COMPILER_CAN_ASSUME(*predicate == ~0l);
}
#undef dispatch_once
#define dispatch_once _dispatch_once
#endif
#endif // DISPATCH_ONCE_INLINE_FASTPATH

Answer 1

In my case it was caused, but no confirmed by logs or exception traces, by the use of KeychainItemWrapper, as recommended here. I dropped that old class and replaced it with the modern solution SAMKeychain.