Index: lib/sanitizer_common/sanitizer_thread_registry.cc
===================================================================
--- lib/sanitizer_common/sanitizer_thread_registry.cc
+++ lib/sanitizer_common/sanitizer_thread_registry.cc
@@ -277,6 +277,8 @@
 }
 
 void ThreadRegistry::QuarantinePush(ThreadContextBase *tctx) {
+  if (tctx->tid == 0)
+    return;  // Don't reuse the main thread.  It's a special snowflake.
   dead_threads_.push_back(tctx);
   if (dead_threads_.size() <= thread_quarantine_size_)
     return;