Hi Frank,
cool to see a life sign of you!
Youre example is one of several reasons for which I do not understand that people keep staying with MAKE, although other build tools exist (for instance SCONS) which do not produce this kind of failures.
the choice of basing our build system on make rather than SCons was actually an informed decision. At an early stage of the project, our build system was ported to SCons by Ludwig Hähne. You can read about his findings here:
http://www.genode-labs.com/publications/scons-vs-make-2008.pdf
In short, his thesis motivated us to reconsider the build system's architecture (based on recursive make) we used back then in favor of our current two-stage build concept. But we stayed with using make as underlying dependency-resolution mechanism.
Cheers Norman