Hi Kai, Tried your settings with no success. Still stopping with the error. There must be something more to it if you managed Desparate as I was, I tried and then kept deleting directories build in which failed (i.e. fpu/cortex-m0) and alas I have built the thing. Still I am not satisfied because I could not compile our interwork enabled projects with just-assembled arm-none-eabi toolchain (something to do with exception unwind though we use only C-code). I remember that I experienced the same thing when building the toolchain for interworking and solved it by rebuilding the toolchain for to good old arm-elf target. The struggle continues... Regards, Andriy