So I just installed qt around 5 minutes ago, and when I wanted to code a simple line of text in the Push Button and try to run it, I got this error:
:-1: error: Coul
add
QMAKE_MAC_SDK = macosx10.12
to your .pro file. Done and Done. (for some, qdevice.pri does not contain the !host_build line, and adding it does nothing, so just set the variable directly in the .pro file).
I have confirmed that you will eventually also have to implement this https://github.com/Homebrew/formula-patches/blob/master/qt5/xcrun-xcode-8.patch: which is just a matter of changing one line in your default_pre.prf file (for your appropriate machine aka Mac/PC, etc...)