Libary not found in QT creator

[DrJones]

I am trying to link OpenCV to my qt project, but for some reason it doesn't seem to able to find my files. my .pro file looks like this

QT       += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = opens
TEMPLATE = app

INCLUDEPATH += /usr/local/include

HEADERS  += mainwindow.h

LIBS += -lm -lopencv_core -lopencv_highgui -lopencv_video -lopencv_imgproc

SOURCES += main.cpp\
        mainwindow.cpp


FORMS    += mainwindow.ui

I get the error message saying

library not found for -lopencv_core

and it is the same for the other ones.


I've been following this guide : https://www.youtube.com/watch?v=i9hYiMXLZRs
What is going on?

[S G H]

Are the libraries in the lib folder?
If you want to keep them in a custom folder, this will work:

LIBS += "-L/my/opencv/libs" -lm -lopencv_core (...)

Otherwise... Probably they're just not there.

[DrJones]

They are in the folder.

[S G H]

Try running the linker in verbose mode (QMAKE_LFLAGS += -v) (not tested).
Check the compile log for all the paths looked for. You can also try to manually add the library's path, to see if the problem persists.

[DrJones]

solution found https://qt-project.org/forums/viewthread/35646