Initial setup:
rustup component add --toolchain nightly llvm-tools-preview
cargo install cargo-fuzz
cargo install grcov
Run the fuzzer for as long as you like:
cargo +nightly fuzz run combo
Generate coverage:
# Run this from the repository root.
make -C fuzz cov
# Output will be in `cov_report/index.html`.
See also the Rust Fuzz Book.