And why would you like to do that? If you didn't dirtied the `Makefile` it doesn't matter you have untracked files, they will not be part of the build (unless, of course, you forgot to commit untracked files in a previous commit or something). And if you did, you'll get the dirty flag anyway.

For me is a big hassle to make untracked files hit the version string with -dirty, because is common for me to have untracked files in the repo that doesn't affect the build at all.