Index: lib/sanitizer_common/sanitizer_mac.cc
===================================================================
--- lib/sanitizer_common/sanitizer_mac.cc
+++ lib/sanitizer_common/sanitizer_mac.cc
@@ -195,7 +195,11 @@
   }
   if (pid == 0) {
     close(master);
-    CHECK_EQ(login_tty(slave), 0);
+    if (login_tty(slave) != 0) {
+      // We already forked, there's not much we can do.  Let's quit.
+      Report("login_tty failed (errno %d)\n", errno);
+      internal__exit(1);
+    }
   } else {
     *amaster = master;
     close(slave);