When i build 1.6.0 InfiniTime Firmware from Scratch - anything is fine, but if i apply a Watchface Modpack (Digistyle Watchface) - it begins to build, but the build process is interrupted with build error and new firmware files are not created. The error messages during build is to fast, so i can't read it.
Maybe you try to build 1.6.0 Infinitime Firmware with applied Digistyle Modpack ?