Problem building kate on neon/plasma docker image

Hi,

I'm using the invent-registry.kde.org/neon/docker-images/plasma:unstable
docker image to build kate.
I get the following cmake configure error:
CMake Error at /usr/lib/x86_64-linux-gnu/cmake/KF6DocTools/KF6DocToolsTargets.cmake:
95 (message):
  The imported target "KF6::DocTools" references the file
     "/usr/lib/x86_64-linux-gnu/libKF6DocTools.so.5.249.0"
instead I have a ibKF6DocTools.so.6.2.0
in this docker image
If I tweak the KF6DocToolsTargets-debug.cmake file accordingly, it builds.
But how did I get to a state where there is such a version mismatch ?
I did apt install kf6-ktexteditor-dev, is this wrong ?

Thanks for any pointers
Alex