Oh, I thought you were talking about running the program. That entire line is for the purpose of removing everything in the current directory except the source files, such as the 'repositories' folder (which is where the program stores downloaded repositories by default) for cleanup purposes.

As for why sudo is there, whenever the download directory for the repositories is rm'd for cleanup, I get a confirmation prompts for each subdirectory:

rm -r repositories/ rm: descend into write-protected directory 'repositories/'? y rm: descend into write-protected directory 'repositories/calculator' ...

So I just use sudo to skip said prompts and documented it.

Another neat way IMO is to provide a Makefile with a clean target.