Gentoo's Bugzilla –
Attachment 557686 Details for
Bug 673036kde-frameworks/kconfig-5.53.0 - CMake Error at /usr/lib64/cmake/Qt5Gui/Qt5GuiConfig.cmake:27 (message): The imported target "Qt5::Gui" references the file "/usr/lib64/qt5/plugins/platformthemes/libqgtk2.so" but this file does not exist.