FATAL: ThreadSanitizer CHECK failed:


Hey guys, I'm having a very strange crash in my project when Tsan is enabled. (Running in simulator)

The console output is:

**FATAL: ThreadSanitizer CHECK failed: /BuildRoot/Library/Caches/com.apple.xbs/Sources/clang_compiler_rt_Fall2018/clang_Fall2018-1000.11.45.2/src/projects/compiler-rt/lib/tsan/rtl/tsan_rtl_proc.cc:48 "((thr->proc1)) == ((nullptr))" (0x200000010e9350, 0x0)**

The thread backtrace looks like:

This error happens pretty randomly, we're playing videos in the app and this happens quite a lot when switching videos.

I'm worried about that this is an indication of a data racing/threading issue in our app. However, unlike normal thread issue where Xcode will pause and show you where in your code the issue happens, this just crashes.

I've Googled a few times but can't find anything even related.

If anyone can give me some advice or help that will be great! Thanks in advance.


And there's another crash which is very similar with the thread backtrace looks like:


These two crashes happen equally randomly.