CMake cannot find packages within Qt6 installation - c++

Question

I am in the process of trying to build a project through CMake and I set environmental variable Qt6_DIR to the directory containing Qt6Config.cmake. However the build doesn't seem to be able to find any of the other dependencies it needs within the Qt6 installation & I'm not sure what needs to be done next. I see references to other possible environmental variables like "Qt6CoreTools_DIR" and I'm wondering if I really need to set each of these independently or if there's a toolchain containing this information that needs to be properly linked to.
-- GUI Frontend: Qt6
CMake Warning at C:/Program Files/CMake/share/cmake-3.20/Modules/CMakeFindDependencyMacro.cmake:47 (find_package):
By not providing "FindQt6CoreTools.cmake" in CMAKE_MODULE_PATH this project
has asked CMake to find a package configuration file provided by
"Qt6CoreTools", but CMake did not find one.
Could not find a package configuration file provided by "Qt6CoreTools"
(requested version 6.2.3) with any of the following names:
Qt6CoreToolsConfig.cmake
qt6coretools-config.cmake
Add the installation prefix of "Qt6CoreTools" to CMAKE_PREFIX_PATH or set
"Qt6CoreTools_DIR" to a directory containing one of the above files. If
"Qt6CoreTools" provides a separate development package or SDK, be sure it
has been installed.
Call Stack (most recent call first):
C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6WidgetsTools/Qt6WidgetsToolsDependencies.cmake:9 (find_dependency)
C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6WidgetsTools/Qt6WidgetsToolsConfig.cmake:34 (include)
C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6Widgets/Qt6WidgetsDependencies.cmake:71 (find_package)
C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6Widgets/Qt6WidgetsConfig.cmake:40 (include)
C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6/Qt6Config.cmake:177 (find_package)
src/CMakeLists.txt:22 (find_package)
CMake Warning at C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6Widgets/Qt6WidgetsDependencies.cmake:71 (find_package):
Found package configuration file:
C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6WidgetsTools/Qt6WidgetsToolsConfig.cmake
but it set Qt6WidgetsTools_FOUND to FALSE so package "Qt6WidgetsTools" is
considered to be NOT FOUND. Reason given by package:
Qt6WidgetsTools could not be found because dependency Qt6CoreTools could
not be found.
Call Stack (most recent call first):
C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6Widgets/Qt6WidgetsConfig.cmake:40 (include)
C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6/Qt6Config.cmake:177 (find_package)
src/CMakeLists.txt:22 (find_package)
CMake Warning at C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6/Qt6Config.cmake:177 (find_package):
Found package configuration file:
C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6Widgets/Qt6WidgetsConfig.cmake
but it set Qt6Widgets_FOUND to FALSE so package "Qt6Widgets" is considered
to be NOT FOUND. Reason given by package:
Target "Qt6::Widgets" was not found.
Call Stack (most recent call first):
src/CMakeLists.txt:22 (find_package)
-- Could NOT find WrapVulkanHeaders (missing: Vulkan_INCLUDE_DIR)
-- Could NOT find Qt6CoreTools (missing: Qt6CoreTools_DIR)
CMake Warning at C:/Program Files/CMake/share/cmake-3.20/Modules/CMakeFindDependencyMacro.cmake:47 (find_package):
Found package configuration file:
C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6Core/Qt6CoreConfig.cmake
but it set Qt6Core_FOUND to FALSE so package "Qt6Core" is considered to be
NOT FOUND. Reason given by package:
Target "Qt6::Core" was not found.
Call Stack (most recent call first):
C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6/QtPublicDependencyHelpers.cmake:14 (find_dependency)
C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6OpenGL/Qt6OpenGLDependencies.cmake:91 (_qt_internal_find_dependencies)
C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6OpenGL/Qt6OpenGLConfig.cmake:40 (include)
C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6/Qt6Config.cmake:177 (find_package)
src/CMakeLists.txt:22 (find_package)
CMake Warning at C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6/Qt6Config.cmake:177 (find_package):
Found package configuration file:
C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6OpenGL/Qt6OpenGLConfig.cmake
but it set Qt6OpenGL_FOUND to FALSE so package "Qt6OpenGL" is considered to
be NOT FOUND. Reason given by package:
Qt6OpenGL could not be found because dependency Qt6Core could not be found.
Call Stack (most recent call first):
src/CMakeLists.txt:22 (find_package)
-- Could NOT find WrapVulkanHeaders (missing: Vulkan_INCLUDE_DIR)
-- Could NOT find Qt6CoreTools (missing: Qt6CoreTools_DIR)
CMake Warning at C:/Program Files/CMake/share/cmake-3.20/Modules/CMakeFindDependencyMacro.cmake:47 (find_package):
Found package configuration file:
C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6Core/Qt6CoreConfig.cmake
but it set Qt6Core_FOUND to FALSE so package "Qt6Core" is considered to be
NOT FOUND. Reason given by package:
Target "Qt6::Core" was not found.
Call Stack (most recent call first):
C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6/QtPublicDependencyHelpers.cmake:14 (find_dependency)
C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6OpenGL/Qt6OpenGLDependencies.cmake:91 (_qt_internal_find_dependencies)
C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6OpenGL/Qt6OpenGLConfig.cmake:40 (include)
C:/Program Files/CMake/share/cmake-3.20/Modules/CMakeFindDependencyMacro.cmake:47 (find_package)
C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6/QtPublicDependencyHelpers.cmake:14 (find_dependency)
C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6OpenGLWidgets/Qt6OpenGLWidgetsDependencies.cmake:91 (_qt_internal_find_dependencies)
C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6OpenGLWidgets/Qt6OpenGLWidgetsConfig.cmake:40 (include)
C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6/Qt6Config.cmake:177 (find_package)
src/CMakeLists.txt:22 (find_package)
CMake Warning at C:/Program Files/CMake/share/cmake-3.20/Modules/CMakeFindDependencyMacro.cmake:47 (find_package):
Found package configuration file:
C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6OpenGL/Qt6OpenGLConfig.cmake
but it set Qt6OpenGL_FOUND to FALSE so package "Qt6OpenGL" is considered to
be NOT FOUND. Reason given by package:
Qt6OpenGL could not be found because dependency Qt6Core could not be found.
Call Stack (most recent call first):
C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6/QtPublicDependencyHelpers.cmake:14 (find_dependency)
C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6OpenGLWidgets/Qt6OpenGLWidgetsDependencies.cmake:91 (_qt_internal_find_dependencies)
C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6OpenGLWidgets/Qt6OpenGLWidgetsConfig.cmake:40 (include)
C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6/Qt6Config.cmake:177 (find_package)
src/CMakeLists.txt:22 (find_package)
CMake Warning at C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6/Qt6Config.cmake:177 (find_package):
Found package configuration file:
C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6OpenGLWidgets/Qt6OpenGLWidgetsConfig.cmake
but it set Qt6OpenGLWidgets_FOUND to FALSE so package "Qt6OpenGLWidgets" is
considered to be NOT FOUND. Reason given by package:
Qt6OpenGLWidgets could not be found because dependency Qt6OpenGL could not
be found.
Call Stack (most recent call first):
src/CMakeLists.txt:22 (find_package)
CMake Error at src/CMakeLists.txt:22 (find_package):
Found package configuration file:
C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6/Qt6Config.cmake
but it set Qt6_FOUND to FALSE so package "Qt6" is considered to be NOT
FOUND. Reason given by package:
Failed to find Qt component "Widgets".
Expected Config file at
"C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6Widgets/Qt6WidgetsConfig.cmake" exists
Failed to find Qt component "OpenGL".
Expected Config file at
"C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6OpenGL/Qt6OpenGLConfig.cmake" exists
Failed to find Qt component "OpenGLWidgets".
Expected Config file at
"C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6OpenGLWidgets/Qt6OpenGLWidgetsConfig.cmake"
exists

Answer 1

According to QTBUG-97615 the proper support of configuring the build with single Qt6_DIR isn't supported (yet?), and the 'official' way to configure your application build is to use CMAKE_PREFIX_PATH (as suggested in other answers).
However if your tools don't support such appoach easily (like VisualStudio/VSCode), there is a workaround for such case (I've discovered it while digging the messy cmake-scripts of Qt6).
You can use QT_ADDITIONAL_PACKAGES_PREFIX_PATH to specify the Qt root (along with Qt6_DIR to hook it initially).
And the command line will look as follows (just to illustrate the approach):
cmake -DQt6_DIR:PATH=C:/Qt6/6.2.3/mingw_64/lib/cmake/Qt6 -DQT_ADDITIONAL_PACKAGES_PREFIX_PATH=C:/Qt6/6.2.3/mingw_64 ..
Both these variables are easily configurable through UI in VisualStudio/VSCode.
Happy building! :)

Answer 2

Add this to your root cmake.
list(APPEND CMAKE_PREFIX_PATH "~/Qt/6.3.0/gcc_64")
Change the path as needed.
Alternatively You can set it as env var.
export PATH="~/Qt/6.3.0/gcc_64/:$PATH"

Answer 3

Since I see some people in the comments asking specifically for VS(-Code) settings/configuration, the following worked for me on Windows:
I set CMAKE_PREFIX_PATH to C:/Qt/6.4.2/msvc2019_64 (substitute C:/Qt/6.4.2 with your Qt installation path and version).
Note: with Qt 5, you could use [..]/msvc2019_64/lib/cmake, this doesn't work for Qt 6 anymore. If you need multiple paths in CMAKE_PREFIX_PATH, join them with a semicolon (;).
An example .vscode/settings.json could look like this:
{
"cmake.configureSettings": {
"CMAKE_PREFIX_PATH": "C:/Qt/6.4.2/msvc2019_64"
}
}

Answer 4

From Qt Documentation:
There are different ways you can tell CMake about Qt, but the most common and recommended approach is to set the CMake cache variable CMAKE_PREFIX_PATH to include the Qt 6 installation prefix.
So you shoud add C:/Qt6/6.2.3/mingw_64/ to the CMAKE_PREFIX_PATH semicolon-separated list.

Answer 5

You could check whether CMAKE_PREFIX_PATH is set or modified by one of the cmake scripts supplied by the project.
I had the same problem with a different project on Linux OS and what seemed to work in the end was setting a project specific variable named QT_PREFIX to /opt/Qt/6.2.4/gcc_64/.
By looking at the project's file CMakeLists_Dependencies.cmake I noticed that CMAKE_PREFIX_PATH was being set by the script like this:
set(CMAKE_PREFIX_PATH "${QT_PREFIX}/lib/cmake").
My guess is, that this statement shadowed my definition of CMAKE_PREFIX_PATH from the command line.
I checked it by inserting the statement message(CMAKE_PREFIX_PATH="${CMAKE_PREFIX_PATH}") right below set(CMAKE_PREFIX_PATH "${QT_PREFIX}/lib/cmake").
When not setting QT_PREFIX, the output was CMAKE_PREFIX_PATH="/lib/cmake", no matter whether I included -DCMAKE_PREFIX_PATH=… on the command line or not. (/lib/cmake/ was not a valid path in my case.)
If QT_DIR was set as described above, the output was CMAKE_PREFIX_PATH="/opt/Qt/6.2.4/gcc_64//lib/cmake", which enabled cmake to find the directory, even despite the double slash.