Sorry, I might be wrong on this point, actually I tried, but I didn't figure out how to do that.Should this code rather be in a different .pm and the user selects which one to use via the .ini file?Yes, that's also what I thought. Then we need to change a little in upper level, e.g. OMPI.pm, we should test the environment and compiler, in order to choose the right install module (Gnu_install.pm or Win_install.pm maybe).
Thanks, Shiqing