Index: lib/sanitizer_common/sanitizer_stacktrace_libcdep.cc
===================================================================
--- lib/sanitizer_common/sanitizer_stacktrace_libcdep.cc
+++ lib/sanitizer_common/sanitizer_stacktrace_libcdep.cc
@@ -43,7 +43,12 @@
       if (dedup_frames-- > 0) {
         if (dedup_token.length())
           dedup_token.append("--");
-        dedup_token.append(cur->info.function);
+        if (cur->info.function != nullptr) {
+          dedup_token.append(cur->info.function);
+        } else {
+          Printf(
+              "ERROR: symbolication missing, is llvm-symbolizer in $PATH?\n");
+        }
       }
     }
     frames->ClearAll();