If you face any difficulty installing iraspa, the following additional steps helped me successfully installing and I thought I would share them with you:
Steps as mentioned in the section 1.3 of the raspa2 manual:
Open terminal in macOS
1. git clone https://github.com/iraspa/RASPA2
2. export RASPA DIR=${HOME}/RASPA/simulations/
3. rm -rf autom4te.cache
4. mkdir m4
5. (new step) /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
6. (new step) brew install automake (This is to install aclocal)
7. (New step) brew install libtool (This is to run autoreconf and make)
8. aclocal
9. autoreconf -i
10. automake --add-missing
11. autoconf
12. ./configure --prefix=${RASPA_DIR}
13. make