If i run the python script in MSYS32, i also have a very long build time (more than hour).
So this is not related to eclipse.
Any idea?

Hello all, I have an issue with Eclipse. Everything was working fine but building time was a little bit slow. Quite normal under windows 10 and MSYS32. For other reasons i tried activating WSL on windows. Since that moment, building under Eclipse didn't work. So i disabled WSL and now building works...