QML module not found when using KDE Kirigami - qt

Question

So I decided to use KDE Kirigami UI framework in my app so I followed the instructions here. I cloned the repo in my app directory and then added it with a simple include(kirigami/kirigami.pri) in my project file.
Now this works, however the problem I encountered is that in QML there is always the error: QML module not found when I import the plugin (import org.kde.kirigami 2.9). The project still compiles and runs just fine and I am able to use the UI components I need, however the major issue is that code completion and syntax highlighting for the Kirigami plugin do not work.
A similar question has been asked before here, I have tried all the suggestions in the answers of that thread but none of them worked:
I imported QQmlEngine::addImportPath the kirigami/src/controls folders using absolute and relative paths. I also tried with qrc:/.
I added a QML_IMPORT_PATH += $$PWD/kirigami/src/controls $$PWD/kirigami line to my project file.

Answer 1

When you mouse over the "module org.kde.kirigami not found" error marker in a QML file, the popup tells you that Qt Creator is looking in QML_IMPORT_PATH for these files. It also tells you how to set this.
By adding QML_IMPORT_PATH += … to your project file, you have set it for a qmake based build process. However, Kirigami projects usually use CMake, and that might be the reason why your previous attempts did not work out.
To set QML_IMPORT_PATH for a CMake based build system, you would open the CMakeLists.txt file from the root of your project tree and add the following section on top:
# ------------------------- BEGIN: lists to maintain manually -------------------------
# Directories where Qt Creator can find QML files of Kirigami etc. on your system.
# (This setting is cached in variable QML_IMPORT_DIR, see below. Delete
# ${BUIL_DIR}/CMakeCache.txt to make make changes here effective.)
list(APPEND QML_DIRS "/usr/lib/x86_64-linux-gnu/qt5/qml")
# ------------------------- END: lists to maintain manually -------------------------
# Tell Qt Creator where to find QML files.
# (The build process will work without this, but no code completion etc..)
set(
QML_IMPORT_PATH "${QML_DIRS}"
CACHE STRING "Qt Creator 4.1 extra qml import paths"
)
Of course, adapt it to the correct directory for your system. On a Debian / Ubuntu based system, the following will determine the directory containing Kirigami QML files installed from the repositories:
dpkg -L qml-module-org-kde-kirigami2 | grep "\.qml"
Source: another answer on StackOverflow