Admittedly, and while I do use Debian forks (e.g. Ubuntu), I did not use much Debian itself (and never for compiling my software)... Apparently, very few people are using it to build the viewer, since in all these years, this is the first such report !
Anyway, `uname -m` is now used in the viewer build script. Hopefully, no one will come back and tell me it does not work for their distro !