This post was closed and I've tried to improve it. Any other suggestions?
You have to understand that we get piles of questions every day that consist of little more than "here's my code, find the bug in it" or "my application crashed, tell me why." In general, these very application-specific questions aren't received well. When a flag is raised on a debugging question (as happened with yours), it can sometimes be very hard to tell the difference between a question that has lasting value and one where the asker is just trying to have us do their job for them.
I think you have an interesting question here, and it has the potential to be an issue that many others will encounter. You did a good job with your edits, particularly the addition of the code where your application is crashing.
The elements that make your question of broad interest are the third-party library involved (I've heard of a number of a number of people using PJSIP on iOS), the odd stack trace pointing to something in that library, and the fact that this crash occurs under very specific circumstances with a new compiler. I think you've done a good job of highlighting these facts, but sometimes people need to more explicitly point out unique problem characteristics like this. You'll notice I asked for a little more detail in my follow-on comment about which compilers were used, because this is information that can add even more value to your question (and make it easier to answer).
If you think the person or people who closed your question misunderstood it or didn't see the value in it, the first thing to do is to check and make sure your question was as clear as you think it was. If you still feel good about what was asked (or you've edited to refine the question), you can flag for moderator attention and use a custom flag to explain why you feel this ought to be reopened. We take a look at all of these. Finally, if you feel a flag couldn't convey why this should be reopened, or you'd like more feedback about why it was closed and how to fix that, you can ask about it on Meta.
In the end, things worked out here. Your question was reopened by the community, and the votes for it reflect the interest in what you're asking.
You can edit your post making the required corrections and then flag the post to review for reopening. This is what i have done to reopen my closed post.