Updating the KDE Plasma Desktop in our Gentoo workstations this time failed with
CMake Error at /usr/share/cmake/Modules/CMakeFindDependencyMacro.cmake:48 (find_package): Found package configuration file: /usr/lib64/cmake/Qt5WebKit/Qt5WebKitConfig.cmake but it set Qt5WebKit_FOUND to FALSE so package "Qt5WebKit" is considered to be NOT FOUND. Reason given by package: Qt5WebKit could not be found because dependency is required to have exact version 5.11.x.
It was strange because the previous emerge included the QT upgrade from old 5.11.2 to 5.12.1 and this dependency should have been resolved properly before:
emerge -vau $(qlist -IC|grep dev-qt|sort|uniq)
But apparently despite that the emerge built all QT libraries in dependency order the “dev-qt/qtwebkit” was built against the old QT libraries. And this is what is saying the above error!
The solution is really simple just rebuild the dev-qt/qtwebkit
root@srv ~ # emerge -va dev-qt/qtwebkit These are the packages that would be merged, in order: Calculating dependencies... done! [ebuild R ] dev-qt/qtwebkit-5.212.0_pre20180120:5/5.212::gentoo USE="X geolocation hyphen jit multimedia opengl printsupport qml -gles2 -gstreamer -nsplugin -orientation -webp" 0 KiB Total: 1 package (1 reinstall), Size of downloads: 0 KiB Would you like to merge these packages? [Yes/No] yes