Cannot compile first example of "Qt for Beginners" wiki page

Dekeon

Hi,

I've followed the first steps of this guide:
https://wiki.qt.io/Qt_for_Beginners

I've created an Empty qmake Project. I've then put the following code in my .pro file [Snake.pro] (copy-pasted from the guide) :

TEMPLATE = app
TARGET = name_of_the_app

QT = core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

SOURCES +=  main.cpp

Then, I made a C++ source file [main.cpp] in which I put (again, copy-pasted):

//
#include <QApplication>
#include <QPushButton>

int main(int argc, char **argv)
{
 QApplication app (argc, argv);

 QPushButton button ("Hello world !");
 button.show();

 return app.exec();
}
//

When I try to run it, I get the following errors:

D:\OneDrive\Documents\C++\Qt\build-Snake-Desktop_Qt_5_10_0_MSVC2013_64bit-Debug\debug\main.o:-1: In function Z5qMainiPPc': D:\OneDrive\Documents\C++\Qt\Snake\main.cpp:6: error: undefined reference to _imp___ZN12QApplicationC1ERiPPci'
D:\OneDrive\Documents\C++\Qt\Snake\main.cpp:8: error: undefined reference to _imp___ZN11QPushButtonC1ERK7QStringP7QWidget' D:\OneDrive\Documents\C++\Qt\Snake\main.cpp:9: error: undefined reference to _imp___ZN7QWidget4showEv'
D:\OneDrive\Documents\C++\Qt\Snake\main.cpp:8: error: undefined reference to _imp___ZN11QPushButtonD1Ev' [5 to 10 more undefined reference to errors...] crt0_c.c:-1: error: undefined reference to WinMain@16'
collect2.exe:-1: error: error: ld returned 1 exit status

How can I fix this? I'm on Windows 10, and the kit I'm using for my project is Desktop Qt 5.10.0 MinGW 32bit with the selected compiler MinGW 5.3.0 32bit for C++.

Thanks!

Charlie_Hdz

Welcome @Dekeon

Can you try to run a QWidget project?

Dekeon

I made a Qt Widget and I got the same result, but with a bunch more errors of the same kind:
undefined reference to...

Charlie_Hdz

@Dekeon said in Can not compile first example of "Qt for Beginners" wiki page:

I made a Qt Widget and I got the same result, but with a bunch more errors of the same kind:
undefined reference to...

Please go to Tools->Options->Build&Run and take a screenshot of the Kits tab

Dekeon

It's quite a mess, I've made default the only kit which doesn't have a red exclamation sign.

Charlie_Hdz

Can you add widget in the following way (file .pro)?

QT = core gui widgets

Dekeon

@Charlie_Hdz said in Cannot compile first example of "Qt for Beginners" wiki page:

QT = core gui widgets

Tried in both the projects, getting the same errors still.

Charlie_Hdz

Here is another solution:

You have a mismatch between VS libraries and MINGW... Trying downloading the VS kit from https://www1.qt.io/download/

Dekeon

What does VS stand for? I don't see anything resembling VS kit to download anywhere. Do I have to redownload the open source?

Charlie_Hdz

I got the same issue a time ago, having VS and using Qt Creator in the same OS...

Show me the issue description of the kits.
Can you delete all the kits that had issues.
Display the DEsktop MinGW kit and show me the information there.

Dekeon

Here's the informations about a kit with a red sign:

Here's the one I've selected as default:

I can't seem to be able to delete the ones that are marked red. I've tried the maintenance tool, but I don't know what to de-select and if it's even the right thing to do. Here's my maintenance tool selection screen anyways:

JKSH

@Dekeon said in Cannot compile first example of "Qt for Beginners" wiki page:

What does VS stand for? I don't see anything resembling VS kit to download anywhere.

"VS" stands for "Visual Studio" by Microsoft. It is also known as "MSVC" ("Microsoft Visual C/C++").

If you want to use a VS/MSVC kit, then you need to download Visual Studio from Microsoft. However, since you already have MinGW installed, you can just use the MinGW kit.

@Dekeon said in Cannot compile first example of "Qt for Beginners" wiki page:

I can't seem to be able to delete the ones that are marked red. I've tried the maintenance tool, but I don't know what to de-select and if it's even the right thing to do. Here's my maintenance tool selection screen anyways:

The red exclamation marks are there because you have installed kits that you can't use (for example, you haven't installed MSVC so you can't use the MSVC kits).

Expand "Qt 5.10.0" and untick all the MSVC, UWP, and Android kits. Make sure you leave the MinGW kit installed.

Charlie_Hdz

@Dekeon

To expand @JKSH explanation... I did a test in my rusty Windows (I prefer Linux) with your code. It compiled.

I attached some figures for your reference in the Compiler/Kits configuration. (Qt 5.7.1 (MSVC 2015 32 bits)

Hope your application works.. I remembered that I had issues when I got Qt Creator when I had VS installed. So feel accompanied!

Dekeon

It works!!!! It was just a matter of removing the MSVC, UWP and Android kits! Thank you guys for your help!

Charlie_Hdz

@Dekeon

Good news, can you set the thread as Solved, please?