Best strategy and overall probability of success estimation for getting dated C++ - Ruby program to compile

Question

This question has been edited in reaction to the helpful comments, thanks!

I am trying to get this PersonalRapidTransit simulation to run. It was written by John Lees-Miller 13 years ago. Unfortunately the Github repository is closed so I could not open an issue there.

The C++ code is exposed to Ruby using a wrapper that is automatically generated by SWIG. For now my idea is to use old C++ and Ruby. For this I use the compiler flag c++11 or c++03, but I did not manage to install an older version of Ruby on my Ubuntu 24 system yet. I tried it with RUBY_CONFIGURE_OPTS=--with-openssl-dir=$OPENSSL rbenv install 1.9.2-p330 and and the ruby version manager rmv, but ruby --version always returns ruby-3.2.3. Should I maybe rather try to it the other way round, i.e. adapting the C++-code to C++17 and using a new Swig to generate up to date Ruby code?

The complete output from running make in the terminal can be seen here.

Resuming: What is the most probable to work/be true?

1. Use C++03 or 11 and Ruby 1.9.2 to use the code as it is.
2. Adapt the code, and regenerate with new swig to use up to date versions of C++ and Ruby.
3. Success chances of both option above are very low.