Hi, @bmorgan! I don’t have the new beta locally; the GEANT4_USE_PYTHON option is in 10.6.p02.
I’ve confirmed that if I set those three options together in 10.6.p02, I no longer get the error quoted by the OP. But I do get a complaint about Boost not found (this is on my MacBook Pro):
CMake Error at /usr/local/Cellar/cmake/3.15.2/share/cmake/Modules/FindPackageHandleStandardArgs.cmake:137 (message):
Could NOT find Boost (missing: Boost_INCLUDE_DIR python)
Call Stack (most recent call first):
This isn’t a problem for my own work, but I thought I’d pass it along.