What is genext2fs you ask? Simply, it generates an ext2 filesystem as a normal (i.e. non-root) user. It doesn't require you to mount the image file to copy files on it. It doesn't even require you to be the superuser to make device nodes or set group/user ids.
You probably already have genext2fs in your linux distro packages.
If you want bugfixes and nicer features though, you will have to grab the source from github and build it yourself.
The best way to handle bugs/patches/etc... is to file an issue, although the project is kind of hibernating right now.