But be careful with extras-devel, only install packages which are known to work and which you really need. To make an upgrade on extras-devel could upgrade packages which are broken. When your host (N900) is on cssu-testing then you should do an upgrade on your build environment with cssu-testing.

Not in all cases this is needed or will harm the environment, it depends on the packages you really need for building or which you have installed. But this is my recommandation to be on the save side. And you need to compile and install libc first then recompile and install libglib, rcompile and install fcam-drivers, after this your are safe to go for recompiling fcam-applications.