I downloaded the SDK zip file for Linux, followed README file. First, it is good to write how to install dependencies! especially for beginners like me.
Second, even if you install cyusb_linux GUI app, still when try to build a firmware using mkdir build, build , cmake .., make . you get many errors! one obvious one is to give the ARM compiler file gcc and gpp compilers.
it is good to add step by step and in easy word the procedure.
Could you share some screenshots to show the problem? I have no idea which problem you are facing to just by your description.