[SOLVED] How to fix error when using OpenCV in Clion

Issue

I'm trying to use OpenCV in Clion and I followed this tutorial. I installed opencv with choco install opencv

But after running the program I get this error:

D:\Apps\CLion 2022.3.1\bin\mingw\bin/ld.exe: cannot find -lopencv_core
D:\Apps\CLion 2022.3.1\bin\mingw\bin/ld.exe: cannot find -lopencv_imgproc
D:\Apps\CLion 2022.3.1\bin\mingw\bin/ld.exe: cannot find -lopencv_highgui
D:\Apps\CLion 2022.3.1\bin\mingw\bin/ld.exe: cannot find -lopencv_imgcodecs
collect2.exe: error: ld returned 1 exit status
ninja: build stopped: subcommand failed.

This is my CMakeLists.txt:

cmake_minimum_required(VERSION 3.24)
project(GTSpeed)

set(CMAKE_CXX_STANDARD 17)

set(ENV{OPENCV_DIR} "C:\\tools\\opencv\\build")
set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/cmake/")

find_package(OpenCV REQUIRED)
include_directories(${OpenCV_INCLUDE_DIRS})

add_executable(GTSpeed main.cpp gtspeed/Keyboard.cpp gtspeed/Keyboard.h gtspeed/Logger.cpp gtspeed/Logger.h gtspeed/Config.cpp gtspeed/Config.h)
#add_executable(GTSpeed main.cpp)

set(OpenCV_LIBS opencv_core opencv_imgproc opencv_highgui opencv_imgcodecs)
target_link_libraries(GTSpeed ${OpenCV_LIBS})

My system environment variables:

And this is my user variable for path:

C:\tools\opencv\build\x64\vc15\bin

I searched this online but there weren't answers for Clion and opencv in c++.

Also before I got this error it had another issue but I solved it.

CMake Error at CMakeLists.txt:9 (find_package):
  Found package configuration file:

    C:/tools/opencv/build/OpenCVConfig.cmake

  but it set OpenCV_FOUND to FALSE so package "OpenCV" is considered to be
  NOT FOUND.

So I went in the file and changed set(OpenCV_FOUND FALSE) to TRUE. I don't know if this affected anything.

Thanks.

Solution

It appears to me that you are building using mingw however your C:\tools\opencv\build\x64\vc15\bin seems to be pointing to libraries built using MSVC. As is seen from the vc15.

You either need to build OpenCV libraries using mingw or you need to use MSVC for your project.

Hope it helps!

EDIT: I did not notice your EDIT... that is definitely a bad idea. OpenCV_FOUND is set by CMake (specifically the FindCMake.cmake or similar config files). DO NOT set this manually yourself.

EDIT2: Here is a link on how to configure CLion so that it uses MSVC

Answered By - Milan Š.

Answer Checked By - Katrina (WPSolving Volunteer)