libFuzzer newbie question

So I was curious to start using the libFuzzer, but trying to follow along I got the following error:

clang++ -fsanitize=address -fsanitize-coverage=edge Fuzzer*.o

Undefined symbols for architecture x86_64:

“_dfsan_create_label”, referenced from:

fuzzer::TraceState::DFSanCmpCallback(unsigned long, unsigned long, unsigned long, unsigned long long, unsigned long long, unsigned short, unsigned short) in FuzzerTraceState.o

fuzzer::Fuzzer::InitializeTraceState() in FuzzerTraceState.o

“_dfsan_get_label_info”, referenced from:

fuzzer::TraceState::GetLabelRange(unsigned short) in FuzzerTraceState.o

“_dfsan_read_label”, referenced from:

_dfsan_weak_hook_memcmp in FuzzerTraceState.o

“_dfsan_set_label”, referenced from:

fuzzer::Fuzzer::InitializeTraceState() in FuzzerTraceState.o

ld: symbol(s) not found for architecture x86_64

clang-3.7: error: linker command failed with exit code 1 (use -v to see invocation)

Any hints as to what I’m doing wrong? Thanks

Explicitly CC-ing Kostya…

I hope I’ve replied in another related thread.