gitflow's last update was about 4 and a half years ago. It's no longer maintained so no new features and more importantly no bug fixes. gitflow-avh is the most popular fork of gitflow and remains active to this day. According to the author of gitflow-avh both Debian and Ubuntu have switched to his fork to provide the git-flow package which is a very good indicator that the original project has died and that AVH is a suitable alternative.
Customer support service by UserEcho