Index: compiler-rt/lib/fuzzer/FuzzerExtFunctions.def
===================================================================
--- compiler-rt/lib/fuzzer/FuzzerExtFunctions.def
+++ compiler-rt/lib/fuzzer/FuzzerExtFunctions.def
@@ -33,6 +33,7 @@
          (void (*malloc_hook)(const volatile void *, size_t),
           void (*free_hook)(const volatile void *)),
          false);
+EXT_FUNC(__sanitizer_log_write, void, (const char *buf, size_t len), false);
 EXT_FUNC(__sanitizer_purge_allocator, void, (), false);
 EXT_FUNC(__sanitizer_print_memory_profile, void, (size_t, size_t), false);
 EXT_FUNC(__sanitizer_print_stack_trace, void, (), true);
Index: compiler-rt/lib/fuzzer/FuzzerUtilFuchsia.cpp
===================================================================
--- compiler-rt/lib/fuzzer/FuzzerUtilFuchsia.cpp
+++ compiler-rt/lib/fuzzer/FuzzerUtilFuchsia.cpp
@@ -311,6 +311,17 @@
 
 // Platform specific functions.
 void SetSignalHandler(const FuzzingOptions &Options) {
+  // Make sure information from libFuzzer and the sanitizers are easy to
+  // reassemble. `__sanitizer_log_write` has the added benefit of ensuring the
+  // DSO map is always available for the symbolizer.
+  // A uint64_t fits in 20 chars, so 64 is plenty.
+  char Buf[64];
+  memset(Buf, 0, sizeof(Buf));
+  snprintf(Buf, sizeof(Buf), "==%lu== INFO: libFuzzer starting.\n", GetPid());
+  if (EF->__sanitizer_log_write)
+    __sanitizer_log_write(Buf, sizeof(Buf));
+  Printf("%s", Buf);
+
   // Set up alarm handler if needed.
   if (Options.UnitTimeoutSec > 0) {
     std::thread T(AlarmHandler, Options.UnitTimeoutSec / 2 + 1);