The qtdeclarative recipe manually copied include files, which missed
the build-time generated qfeatures.h. Without it, downstream consumers
(SDDM, KWin, etc.) hit 'division by zero in #if' errors in qquickitem.h
because QT_CONFIG(quick_shadereffect) and QT_CONFIG(quick_draganddrop)
were undefined, triggering the deliberate 1/0 preprocessor trap.
Fix: use cmake --install to properly install all files, and add a safety
net that copies qfeatures.h from the build tree if cmake --install
does not place it in the install prefix.
vasilito
57a3ea6c9e