scripts/sync-e2e-core copies komorebi_vm.core and the unit tests that
belong to it into another directory, and --check says whether the copy is
in step, so that kfw's Windows platform can be written against the code it
will run with while the move is not made. This repository is the source
until the move, and the script goes with it.
Two of those tests imported Rect and Checks from komorebi_vm, which pulls
in the KDE half; they import them from komorebi_vm.core now. The copy
passes its 25 tests in a directory with nothing but pytest and Pillow.
