:-1: error: Project ERROR: Unknown module(s) in QT: mqtt
Installing perl: http://strawberryperl.com/
Installing cmake: https://cmake.org/download/
Installing git: https://gitforwindows.org/
Once installed, I opened git and executed: git clone https://code.qt.io/qt/qtmqtt.git
Then I opened Qtcreator and opened one of the examples from the just downloaded qtmqtt dir. This way I was able to compile and execute an example.
Now I need to find out how to compile it as module. To be continued....
Update:
I am now able to build the mqtt module as well. This is what I did:
Download via git the qtmqtt source files
Open cmd window and run: C:\Qt\5.1\mingw53_32\bin\qtenv2.bat
You will get a response like "Setting up environment for Qt usage...."
cd into dir where git downloaded the source files, like: cd C:\user\myname\qtmqtt
Execute: qmake -r
Execute: C:/Qt/Tools/mingw530_32/bin/mingw32-make install
Now open Qtcreator and build your apps using qtmqtt library.
Note the above assumes that you installed the mingw32 compiler using Qtmaintenance tool.