[CJefferson]

I think one fundamental difference between the two of us (I'm guessing here, let me know if I'm wrong), is I'm willing to cope with longer compile times, as long as I always get a correctly built executable (so there are no 'halting problems', if in doubt, rebuild it!), while you would prefer faster build times, even if that then requires sometimes having to do a little manual work when the build system doesn't realise it needs to rebuild? Of course, no system will be 100% perfect, but you can choose where your trade-off point is.

Two reasonable viewpoints, but probably effects how we do our building setups!

[anyfoo]

I think that's fair. On top of that, being a low level system programmer, I think I'm pretty good at realizing/intuiting when something critical changed that needs me to nuke the build dir, i.e. the manual work you mention to force a full recompile (and also good at noticing mismatched headers even through very weird symptoms).

I do have to switch between multiple SDK versions very often for example, and I always either nuke the build dir after doing that, or have separate build dirs per SDK in the first place.