Unknown module(s) in QT: mqtt

MrHause

Hi,
I have just created the qt quick application that uses qmake. When I want to include mqtt I get the following error:
Project ERROR: Unknown module(s) in QT: mqtt

The documentation says that I have to only write QT += mqtt in .pro file. But it is not working. I have updated my qt to 6.3.2 version. I am using windows system and I can't find any answer for this issue. Do you have any suggestion what is wrong or what should I do step by step?

Best Regards,
Filip

Paul Colby

Hi @MrHause, I've never used the Qt MQTT add-on, but it appears that for that particular add-on (and a few others like it) the The Qt Company only distributes binaries to commercial licensees (the source is still available under GPLv3 though).

I suspect your options are either:

purchase a license; or
build it from source yourself (assuming your application is compatible with the GPLv3).

There seems to be plenty of examples on the Web showing how to build qtmqtt from source, such as this answer.

Cheers.

MrHause

Thank you for the answer and explanation. Unfortunatelly building this was not working for me but after a lot of schearching and struggle I was able to get .dll file.