Fuzz Introspector was reporting a high percentage of fuzz blockers in the fuzz_diff test. This means the fuzzing engine was unable to gain visibility into functions lower in the call stack than the blocking functions, making it less effective at producing interesting input data.

This clears a large percentage of the fuzz blockers by adding fuzzer instrumentation to them via the @atheris.instrument_func decorator.

Fuzz Introspector Before & After Screenshots

Before

After