The job of replacing directories with symlinks apparently is a tough one. Create a symlink manually in the postinst of the affected (!cmake-data) packages.
This package uses quilt for upstream source code patch management. Please read /usr/share/doc/quilt/README.source for more information how to apply, unapply, add, modify or remove patches. Please note that /usr/share/doc/quilt/README.source is only available in quilt version 0.46-4.1 or later.