RUSTFLAGS='-C codegen-units=1' cargo afl build
NOTE: the RUSTFLAGS is only needed on Linux (and not if using gold linker), see rust-lang/rust#53945
cargo afl fuzz -m 200 -i fuzzing_seeds -o out target/debug/png-afl
NOTE: -m 200 sets memory limit to 200 mb. afl defaults to 50 megabytes memory usage. If we would not increase it, many invocations will exit with SIGABRT and look like crashes.