How to integrate QtMultimedia component into a project using CMake? - c++

Question

I'm trying to write a GUI appication (under Ubuntu 18.04) using Qt5 and CMake. I failed to integrate the Qt multimedia module into my project.
My CMakeLists.txt:
cmake_minimum_required(VERSION 3.10)
project(Chess)
#set(CMAKE_PREFIX_PATH "/home/mashplant/Qt5.9.6/5.9.6/gcc_64")
#whether I comment it off or not doesn't have an effect on the result
set(CMAKE_INCLUDE_CURRENT_DIR ON)
set(CMAKE_AUTOMOC ON)
set(CMAKE_AUTOUIC ON)
set(CMAKE_AUTORCC ON)
find_package(Qt5 COMPONENTS Widgets Network Multimedia REQUIRED)
set(CMAKE_CXX_STANDARD 11)
include_directories(.)
add_executable(Main Main.cpp
MainWindow.cpp MainWindow.hpp ChessFrame.cpp ChessFrame.hpp resource.qrc)
target_link_libraries(Main Qt5::Widgets Qt5::Network Qt5::Multimedia)
And I get the following warning when I run CMake:
CMake Warning at CMakeLists.txt:18 (add_executable):
Cannot generate a safe runtime search path for target Main because files in
some directories may conflict with libraries in implicit directories:
runtime library [libQt5Widgets.so.5] in /usr/lib/x86_64-linux-gnu may be hidden by files in:
/home/mashplant/Qt5.9.6/5.9.6/gcc_64/lib
runtime library [libQt5Network.so.5] in /usr/lib/x86_64-linux-gnu may be hidden by files in:
/home/mashplant/Qt5.9.6/5.9.6/gcc_64/lib
runtime library [libQt5Gui.so.5] in /usr/lib/x86_64-linux-gnu may be hidden by files in:
/home/mashplant/Qt5.9.6/5.9.6/gcc_64/lib
runtime library [libQt5Core.so.5] in /usr/lib/x86_64-linux-gnu may be hidden by files in:
/home/mashplant/Qt5.9.6/5.9.6/gcc_64/lib
Some of these libraries may not be found correctly.
And when I compile, I get a link error.
/home/mashplant/Qt5.9.6/5.9.6/gcc_64/lib/libQt5Multimedia.so.5.9.6：undefined reference to ‘operator delete(void*, unsigned long)#Qt_5’
collect2: error: ld returned 1 exit status
CMakeFiles/Main.dir/build.make:203: recipe for target 'Main' failed
make[3]: *** [Main] Error 1
CMakeFiles/Makefile2:67: recipe for target 'CMakeFiles/Main.dir/all' failed
make[2]: *** [CMakeFiles/Main.dir/all] Error 2
CMakeFiles/Makefile2:79: recipe for target 'CMakeFiles/Main.dir/rule' failed
make[1]: *** [CMakeFiles/Main.dir/rule] Error 2
Makefile:118: recipe for target 'Main' failed
make: *** [Main] Error 2

Answer 1

My best bet is that CMake find different components from different installations of Qt. If that's the case, it should be enough to correct all Qt-related CMake variables to point to correct paths (for example, variables like Qt5Widgets_DIR, Qt5Multimedia_DIR, etc.).