Your best bet is to use a pre-packaged setup for your operating system. Known public packaged builds:

• Debian Linux: http://packages.debian.org/gdnsd
• Ubuntu Linux: https://launchpad.net/ubuntu/+source/gdnsd/
• FreeBSD: https://www.freshports.org/dns/gdnsd3
• Arch Linux: https://archlinux.org/packages/extra/x86_64/gdnsd/
• Alpine Linux: https://pkgs.alpinelinux.org/package/edge/community/x86_64/gdnsd
• Void Linux: https://github.com/void-linux/void-packages/tree/master/srcpkgs/gdnsd
• OpenMandriva: https://github.com/OpenMandrivaAssociation/gdnsd
• Raw Source Tarballs (3.x and earlier): https://github.com/gdnsd/gdnsd/releases/