Index: lib/tsan/rtl/tsan_platform_mac.cc
===================================================================
--- lib/tsan/rtl/tsan_platform_mac.cc
+++ lib/tsan/rtl/tsan_platform_mac.cc
@@ -139,7 +139,7 @@
     }
   } else if (event == PTHREAD_INTROSPECTION_THREAD_DESTROY) {
     ThreadState *thr = cur_thread();
-    if (thr->tctx->parent_tid == kInvalidTid) {
+    if (thr->tctx && thr->tctx->parent_tid == kInvalidTid) {
       DestroyThreadState();
     }
   }