I highly recommend ditching Eclipse if you are not already deeply familiar with it. We were encouraged to use it in my Comp Sci 2 class, but it was such a nightmare that I soon jumped back to Emacs and command-line compilation. The only good thing about Eclipse is the built-in Java debugger, but this isn't Java code. In fact, since the project involves cross-compilation with a specific toolchain, it's possible Eclipse can't even handle it--but I don't know that for sure, because Eclipse is a garbage fire I've avoided for the last 15 years. The build instructions at https://github.com/ttrftech/NanoVNA are quite straightforward. We may be able to help figure out what's wrong, but you'd need to give us more information than "make failed". What OS are you using? What steps did you take to get to this point? What was the actual error from make? Getting good at git takes time, but getting "good enough" is pretty easy. Once you figure out the clone, branch, add, commit, and push commands, you're off to a good start.