Extracts hrtmon.rom from WinUAE's source file hrtmon.rom.cpp.
Type
make extract
and it will download hrtmon.rom.cpp from WinUAE Github repository (master), compile the extraction tool and extract hrtmon.rom.
To extract hrtmon.rom from a specific version of hrtmon.rom.cpp you can set the environment variable HRTMON_ROM_CPP_URL:
HRTMON_ROM_CPP_URL=https://raw.githubusercontent.com/tonioni/WinUAE/e7d6f64da6ab5326c1daefbeab4c66c279006f96/hrtmon.rom.cpp make extract