Jordan Petridis created an issue: #701
I stumbled upon this repo today, https://gitlab.gnome.org/GNOME/gnome-hello
Apart from translations the repo hasn't been touched in ages and it doesn't seem relevant anymore according to its readme.
This is GNOME Hello, an example program for my book about GNOME development. GNOME Hello has been ported to the GNOME 2.0 Platform. If you are looking for the original source that corresponds to the book, then you will need to checkout the source from the 'gnome-hello-1-4' branch.
Should get a second opinion though from someone that has been around longer and might know something I miss.