I've modified the tutorial to first mention the https link and then -- for those who have setup the ssh workflow -- the ssh one. thanks for the feedback.
Now, concerning the icons: you have to install scribus before running it:
https://github.com/aoloe/scribus-manual-development/blob/master/content/qt-creator/qt-creator.md#running-your-own-build-of-scribusexplains you how to do it (it took me some time to find all steps but, now, it should be correct!).
After having gone through those two steps, Scribus will find its icons and correctly run (I've tested it!)
Finally, about the IDE:
- personally, i don't use any (but that was not the question, since i'm not in the team; and i would probably use Qt Creator if i needed to use one...).
- Jean uses visual studio on windows
- Craig probably uses QT Creator (i don't think he is using X Code, even if he works on a mac)
- No idea about the others.
- as far as i know, most people compile from the command line or use Qt Creator on Linux.
May I ask you what are your plans with Scribus? : - )