Support installing to /usr or another location requiring sudo access

My preferred workflow when developing in a KDE Neon VM is to overwrite the system packages and install everything to /usr. I currently use raw CMake and make for this, but I would like to switch to kdesrc-build. However I cannot, because it will fail to install to /usr:

cat ~/kde/src/log/2019-03-17-02/kiconthemes/install.log
# kdesrc-build running: 'make' 'install/fast'
# from directory: /home/dev/kde/build/kiconthemes
Install the project...
-- Install configuration: "RelWithDebInfo"
-- Installing: /usr/lib/x86_64-linux-gnu/cmake/KF5IconThemes/KF5IconThemesConfig.cmake
CMake Error at cmake_install.cmake:41 (file):
  file INSTALL cannot copy file
  "/home/dev/kde/build/kiconthemes/KF5IconThemesConfig.cmake" to
  "/usr/lib/x86_64-linux-gnu/cmake/KF5IconThemes/KF5IconThemesConfig.cmake".


Makefile:79: recipe for target 'install/fast' failed
make: *** [install/fast] Error 1

It would be nice if it could run this with sudo in such a circumstance, since then the user could be prompted or could even set up passwordless sudo so the install step can be completed with no further user input required.