Gentoo kde-frameworks/kdewebkit failed compilation with Qt5WebKit could not be found because dependency is required

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:


  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

Keep on reading!