I just installed the latest dev unstable edition of Neon and noticed that KWin doesn't have a dependency to Qt5Multimedia set. At least it's not pulled in. Reproducible: Always Steps to Reproduce: 1. Install neon 2. sudo apt build-dep kwin 3. sudo apt install git 4. git clone git://anongit.kde.org/kwin.git 5. mdkir build 6. cd build 7. cmake ../kwin Actual Results: Output: The following RUNTIME packages have not been found: * Qt5Multimedia Expected Results: Qt5Multimedia being listed as found
I am pretty sure that is because kwin's cmakelists would look for the cmake package of qtmulitmeida which is in libqt5multimedia-dev, but the actual runtime dependency is on the qml module from the package qml-module-qtmultimedia. Latter would be pulled in via recommends of kwin-data, former doesn't ever get pulled in for kwin. That said, perhaps you should check out the way purpose does QML runtime dep checks, IIRC that actually tries to load the qml module instead of going through a cmake package.
As confirmed on IRC the relevant QML module is installed by kwin-data. As far as apt-get build-dep is concerned this is intentional behavior. It simply installs whatever is listed in the control's Build-Depends field and that in turn does not include the QML module as it is a runtime dependency. The build dependency list of the packaging would not include runtime dependencies to reduce build time from unnecessary dependencies. Also as I pointed out this would be better detected by KWin's cmakelists if it used purpose's magic cmake finder for finding qml modules rather than cmake packages (which ultimately suffer from the same problem anyway; i.e. qtmm-dev wouldn't pull in the qml module because it is not actually referenced or needed to build qtmm software).