Qt examples build from archives are supported on Windows only at this moment.
You'll need to get full source code access via git in order to build them (for this you need founding or corporation membership).
If you just want to inspect Qt examples code, download corresponding DrawingsQt archive (note it targtes Windows),
and take Qt folder from there. However, there are no configurations to build it under Linux.
The reason for not having build confgiurations for Linux is that there is no standart Linux setup for Qt, it is usually built locally or for specific distributive.