Client from source won't run/ Possibly outdated script

[Gwynvorth]

I have recently scrubbed my old Windows 7 and set up a new system with a fresh installation of Debian 9 Stretch.
After getting FA to run smoothly under PlayOnLinux I used the instructions shown on the official GitHub to also set up FAF directly under Linux.
Resulting in the attached error message.
Seemed easy enough 'QtWebEngineWidgets' couldn't be accessed, so installed the corresponding package and tried again. Same Error.
Now I looked a little deeper into what the terminal had recently spit out.
It seems like something went wrong during pip installing the requirements. Something interfered with cx_Freeze. I have no idea what or how. Python 3.5.3 is installed and up to date.
Am I missing a package? Did I do something wrong during installation? Or is the script simply outdated and no longer fits commands or package names?

[Wesmania]

That's a case of an inaccurate wiki, I should really fix it. Some packages in requirements.txt are only needed for testing or packaging - cx_Freeze in particular is only used for creating windows MSIs and should be skipped.
I'll check if the logs you posted contain something more, then write another post (things are tough when responding from a phone )

[Gwynvorth]

Have you found anything that might tell us what went wrong and how to fix it?