Whenever an exception happens, it's redirected to the handleCoroutineException() function, which looks like this:

public fun handleCoroutineException(context: CoroutineContext, exception: Throwable) {
    try {
        context[CoroutineExceptionHandler]?.let {
            it.handleException(context, exception)
            return
        }
        
        if (exception is CancellationException) return
        
        context[Job]?.cancel(exception)
        handleCoroutineExceptionImpl(context, exception)
    } catch (handlerException: Throwable) {
        if (handlerException === exception) throw exception
        
        throw RuntimeException(
            "Exception while trying to handle coroutine exception", 
            exception).apply {
                addSuppressedThrowable(handlerException)
            }
    }
}

Let's break down the different parts of this code and analyze what it does.