CMake Variable Reference

Module variables

Qt modules loaded with find_package set various variables.

Note: You rarely need to access these variables directly. Common tasks like linking against a module should be done through the library targets each module defines.

For example, find_package(Qt6 COMPONENTS Widgets), when successful, makes the following variables available:

Variable	Description
Qt6Widgets_COMPILE_DEFINITIONS	A list of compile definitions to use when building against the library.
Qt6Widgets_DEFINITIONS	A list of definitions to use when building against the library.
Qt6Widgets_EXECUTABLE_COMPILE_FLAGS	A string of flags to use when building executables against the library.
Qt6Widgets_FOUND	A boolean that describes whether the module was found successfully.
Qt6Widgets_INCLUDE_DIRS	A list of include directories to use when building against the library.
Qt6Widgets_LIBRARIES	The name of the imported target for the module: Qt5::Widgets
Qt6Widgets_PRIVATE_INCLUDE_DIRS	A list of private include directories to use when building against the library and using private Qt API.
Qt6Widgets_VERSION_STRING	A string containing the module's version.

For all packages found with find_package, equivalents of these variables are available; they are case-sensitive.

Installation variables

Additionally, there are also variables that don't relate to a particular package, but to the Qt installation itself.

Variable	Description
QT_DEFAULT_MAJOR_VERSION	An integer that controls the Qt version that qt_ commands forward to in case of mixed Qt 5 and Qt 6 projects. It needs to be set to either 5 or 6 before the respective find_package() calls. If set to 5, commands starting with qt_ will call their counterpart starting with qt5_. If set to 6, they will call their counterpart starting with qt6_. If not set, the first find_package call defines the default version.
QT_LIBINFIX	A string that holds the infix used in library names, when Qt is configured with -libinfix.
QT_NO_CREATE_VERSIONLESS_FUNCTIONS	Hides commands that start with qt_, leaving only the versioned ones starting with qt6_.
QT_NO_CREATE_VERSIONLESS_TARGETS	Hides the imported targets starting with Qt::. Instead, you need to use the targets starting with Qt6::.
QT_VISIBILITY_AVAILABLE	On Unix, a boolean that describes whether Qt libraries and plugins were compiled with -fvisibility=hidden. This means that only selected symbols are exported.