Fuzz pure Ruby code and Ruby C extensions Make fuzzing easy by providing a RubyGems installation process and simple interface Integrate with the extensive libFuzzer ecosystem Of course, there are many interesting details that go into creating a tool like this but we’ll focus on three: creating a Ruby fuzzing harness, compiling Ruby C extensions with libFuzzer, and adding coverage support for pure Ruby code. Before we proceed, it’s important to understand that there are two Ruby C extensions we are considering: the Ruzzy C extension that hooks into the libFuzzer fuzzing engine and the Ruby C extensions that become our fuzzing targets.