I realized later that the conversation was more about SDL2 than Cmake,
so I wrote the next email about SDL2.
I was surprised that Debian supports SDL2 2.0.5 when they could
probably support SDL2 2.0.18 on any system that has SDL2 2.0.5
I agree that anyone that wishes to compile Hatari on a real old
system can find away to do it without much trouble. SDL2 2.0.5
can easily be updated to 2.0.18 on Centos6, and probably
Debian and Centos5. Therefore upgrading > SDL2 2.0.5 is minor
compared to other changes in Hatari.