QGiS Windows Source Build

xanthas

Hello Community,
I’ve been working with Qt Creator 6 and PyQt5, but recently I needed to use QGIS for map functionality. While attempting to build a simple UI for Windows, I ran into several errors and warning messages during the process. Despite following the Building on Windows guide and trying out the example files from code_examples as well as the Quantum GIS Coding and Compilation Guide, I still encountered issues.

My .pro files look like this:

QT       += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

CONFIG += c++17

DEFINES += QT_DEPRECATED_WARNINGS

# You can make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

SOURCES += \
    main.cpp \
    mainwindow.cpp

HEADERS += \
    mainwindow.h

FORMS += \
    mainwindow.ui

INCLUDEPATH += C:\OSGeo4W\QGIS\src\app C:\OSGeo4W\apps\qgis-qt6-dev\include C:\OSGeo4W\include C:\OSGeo4W\apps\Qt6\include #C:\OSGeo4W\QGIS\src\core C:\OSGeo4W\apps\qgis-dev\include

LIBS += -L"C:\OSGeo4W\apps\qgis-qt6-dev\lib" -lqgis_gui -lqgis_core

# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target

my osgeo4w-build folder and QGIS (git clone) are present inside C:\OSGeo4W location
Please help me !!!

jsulm

@xanthas said in QGiS Windows Source Build:

I still encountered issues

Please also tell us what issues...

xanthas

It gives around 27 different errors like:

:-1: error: C:\Users\D Besta\Documents\simpleqgistest\build\Desktop_Qt_6_6_3_MinGW_64_bit-Debug/../../main.cpp:24: undefined reference to `__imp__ZN19QgsProviderRegistry8instanceERK7QString'
:-1: error: C:\Users\D Besta\Documents\simpleqgistest\build\Desktop_Qt_6_6_3_MinGW_64_bit-Debug/../../main.cpp:27: undefined reference to `__imp__ZN14QgsVectorLayerC1ERK7QStringS2_S2_RKNS_12LayerOptionsE'
:-1: error: C:\Users\D Besta\Documents\simpleqgistest\build\Desktop_Qt_6_6_3_MinGW_64_bit-Debug/../../main.cpp:30: undefined reference to `__imp__ZNK11QgsMapLayer7isValidEv'
:-1: error: C:\Users\D Besta\Documents\simpleqgistest\build\Desktop_Qt_6_6_3_MinGW_64_bit-Debug/../../main.cpp:36: undefined reference to `__imp__ZNK14QgsVectorLayer12geometryTypeEv'
C:\OSGeo4W\apps\qgis-qt6-dev\include\qgis.h:611: error: undefined reference to `__imp__ZN4Qgis16staticMetaObjectE'
:-1: error: [Makefile.Debug:72: debug/simpleqgistest.exe] Error 1

And many other such errors

jsulm

@xanthas You're not linking the libraries properly.
On Windows this is wrong:

LIBS += -L"C:\OSGeo4W\apps\qgis-qt6-dev\lib" -lqgis_gui -lqgis_core

Please take a look at https://doc.qt.io/qt-6/qmake-variable-reference.html#libs and fix this.

xanthas

@jsulm

I have edited the .pro file to:

LIBS += -L"C:\OSGeo4W\apps\qgis-qt6-dev\lib libs" -lqgis_gui -lqgis_core

I also tried:

LIBS += "-LC:\OSGeo4W\apps\qgis-qt6-dev\lib lib" -lqgis_gui -lqgis_core

The file seems to be there but after what you said suggested it is giving me only this error now:

C:\Qt\Tools\mingw1120_64\x86_64-w64-mingw32\bin\ld.exe:-1: cannot find -lqgis_gui
C:\Qt\Tools\mingw1120_64\x86_64-w64-mingw32\bin\ld.exe:-1: cannot find -lqgis_core

When I did this:

LIBS += C:/OSGeo4W/apps/qgis-qt6-dev/lib/qgis_3d.lib C:/OSGeo4W/apps/qgis-qt6-dev/lib/qgis_analysis.lib C:\OSGeo4W\apps\qgis-qt6-dev\lib\qgis_app.lib C:\OSGeo4W\apps\qgis-qt6-dev\lib\qgis_native.lib C:\OSGeo4W\apps\qgis-qt6-dev\lib\qgis_server.lib #-lqgis_gui -lqgis_core

Again all the previous errors mentioned arise

jsulm

@xanthas

LIBS += C:/OSGeo4W/apps/qgis-qt6-dev/lib/qgis_3d.lib \
        C:/OSGeo4W/apps/qgis-qt6-dev/lib/qgis_analysis.lib \
        C:/OSGeo4W/apps/qgis-qt6-dev/lib/qgis_app.lib \
        C:/OSGeo4W/apps/qgis-qt6-dev/lib/qgis_native.lib \
        C:/OSGeo4W/apps/qgis-qt6-dev/lib/qgis_server.lib

Should work (you have \ in the paths which is wrong, don't use \ in in paths in pro files ).
If it does not then next thing to check is: were these libs built using same compiler?
You should also look for the very first linker error/warning.

Christian Ehrlicher

You can not mix visual studio and mingw libraries. Either compile all with msvc or use QGIS compiled against mingw.

xanthas

This post is deleted!

xanthas

@Christian-Ehrlicher @jsulm

@jsulm said in QGiS Windows Source Build:

\ in the paths

used the abovew as path and still I get

@xanthas said in QGiS Windows Source Build:

27 different errors like

jsulm

@xanthas said in QGiS Windows Source Build:

still I get

Then please read what @Christian-Ehrlicher wrote.

xanthas

@Christian-Ehrlicher
@jsulm
i have tried it and it is giving me 179 errors and I can't find any relative help from other forums as well.

Pl45m4

@xanthas said in QGiS Windows Source Build:

i have tried it and it is giving me 179 errors

What did you "try"?
If @Christian-Ehrlicher is correct here with:

You can not mix visual studio and mingw libraries. Either compile all with msvc or use QGIS compiled against mingw.

trying harder won't solve your problem :)

Either switch to MSVC or find another, MinGW supporting, version of QGIS.

xanthas

@Pl45m4
So what I have understood is that when I download all dependencies and build QGiS from source, I should either use Qt to compile and build libraries or else I should use visual studio to build and compile it, right?
Further, to make the UI and backend codes I should use the same compiler from which I had made the QGiS library, Am I right?

What I have understood is the same thing discussed here also, I guess.

jsulm

@xanthas said in QGiS Windows Source Build:

right?

No.
Qt and visual studio are two completely different things.
Qt is a C++ framework, Visual Studio is a IDE.
What @Pl45m4 wrote is: you should use MSVC as compiler + Qt built with MSVC.
Or you find (or build by yourself) QGIS built with MinGW + Qt built with MinGW.
Reason: you cannot mix different C++ compiler (like you do now: MSVC + MinGW).

abhishek999

can you give me step by step procedure to integrate qgis project in qt to show map in qt C++
i am also facing same issue @jsulm

jsulm

@abhishek999 said in QGiS Windows Source Build:

can you give me step by step procedure

In the first post in this thread there is a link to a step by step explanation, follow it...

abhishek999

i am facing prolem Screenshot (10).png

here is my .pro file
QT += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

CONFIG += c++17

You can make your code fail to compile if it uses deprecated APIs.

In order to do so, uncomment the following line.

#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000 # disables all the APIs deprecated before Qt 6.0.0

SOURCES +=
main.cpp
mainwindow.cpp

HEADERS +=
mainwindow.h

FORMS +=
mainwindow.ui

Include QGIS headers and libraries manually

INCLUDEPATH += C:\OSGeo4W\apps\qgis-qt6-dev\include

LIBS += C:/OSGeo4W/apps/qgis-qt6-dev/lib/qgis_3d.lib
C:/OSGeo4W/apps/qgis-qt6-dev/lib/qgis_analysis.lib
C:/OSGeo4W/apps/qgis-qt6-dev/lib/qgis_app.lib
C:/OSGeo4W/apps/qgis-qt6-dev/lib/qgis_native.lib
C:/OSGeo4W/apps/qgis-qt6-dev/lib/qgis_server.lib

INCLUDEPATH += C:/OSGeo4W64/include

Default rules for deployment.

qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target

abhishek999

@jsulm @Christian-Ehrlicher
can you please tell me what exact is the problem i have reinstall qt ,Qgis ,OSGeo4W multiples time but still same problem i am facing

Christian Ehrlicher

You still doing the same thing as in your first post - you use a Qt compiled for MinGW and try to link it against a QGis compiled against MSVC. This will not work out - no matter how often you install something...

abhishek999

can you give me the steps to fix this @Christian-Ehrlicher