Build Errors while building custom Slicer

OS: Ubuntu 20.04
Hi. I have built Slicer (v4.11.20210226) before successfully.
Now, I want to build a custom Slicer with change in logo, style, etc. So, I followed the instructions given in to customize the application. Then, I followed the general Slicer build instructions given in GNU/Linux systems — 3D Slicer documentation

At the end of the build process, I am getting the following errors. Hence, I am unable to locate or run the executable file.

– Configuring incomplete, errors occurred!
See also “/home/karthik/Custom-Slicer/CTFFR-rel/Slicer-build/CMakeFiles/CMakeOutput.log”.
See also “/home/karthik/Custom-Slicer/CTFFR-rel/Slicer-build/CMakeFiles/CMakeError.log”.
make[2]: *** [slicersources-build/CMakeFiles/Slicer.dir/build.make:127: slicersources-build/Slicer-prefix/src/Slicer-stamp/Slicer-configure] Error 1
make[1]: *** [CMakeFiles/Makefile2:173: slicersources-build/CMakeFiles/Slicer.dir/all] Error 2
make: *** [Makefile:84: all] Error 2

I am attaching the log files for reference.

Please help me understand what these errors mean. My custom template directory is named CTFFR and the build directory is named CTFFR-rel.

Also, please give suggestions/instructions to build custom 3D Slicer.

This line:

c++: error: unrecognized command line option ‘-features=no%anachronisms’

indicates that there is some issue with your c++ compiler. Have you built cmake based applications on this machine before?

Yes. I have built 3D Slicer v4.11.20210226 and v4.13. It has been built successfully. The executable works. I have also built extensions on it and packaged them. They all work. But, when I followed the custom template to create a custom 3D Slicer with different logo and style, I am getting these errors.

Are the instructions given here and GNU/Linux systems — 3D Slicer documentation correct? Are there any other references?