[darwinbuild-dev] Can I use Case Sensitive HFS+?

I have an case sensitive HFS+ mounted on /usr/local for all my unixy- stuff. This generally works fine. I have installed darwinbuild on that partition (so it is on case sensitive HFS+). But my first attempt at a build ends with The Mac OS X platform is missing - cannot set a default platform Which is the error (if I understand things correctly) message that appears when you are on HFS+. By mine is case sensitive so I assumed it would be OK as for most intents and purposes case sensitive HFS+ is OK for all my unixy stuff. So, is a UFS dmg really my only option (as I do not want the /usr/ local to be UFS)? Or should it work and is something else amiss? Thanks, Gerben Wierda