Options in CMake for define a path to install Frameworks in macOS

[judaew]

Hi there. I'm the maintainer of the bctoolbox port over at MacPorts.

It looks like the Frameworks installation location is hard-coded in the following lines:

bctoolbox/src/CMakeLists.txt

Lines 286 to 305 in 388770f

	if(ENABLE_SHARED)
	install(TARGETS bctoolbox EXPORT ${EXPORT_TARGETS_NAME}Targets
	RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
	LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
	ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
	FRAMEWORK DESTINATION Frameworks
	PERMISSIONS OWNER_READ OWNER_WRITE OWNER_EXECUTE GROUP_READ GROUP_EXECUTE WORLD_READ WORLD_EXECUTE
	COMPONENT core
	)
	if(ENABLE_TESTS_COMPONENT)
	install(TARGETS bctoolbox-tester EXPORT ${EXPORT_TARGETS_NAME}Targets
	RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
	LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
	ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
	FRAMEWORK DESTINATION Frameworks
	PERMISSIONS OWNER_READ OWNER_WRITE OWNER_EXECUTE GROUP_READ GROUP_EXECUTE WORLD_READ WORLD_EXECUTE
	COMPONENT tester
	)
	endif()
	endif()

... on the line:

FRAMEWORK DESTINATION Frameworks

MacPorts uses the following directory for frameworks: ${prefix}/Library/Frameworks. For example:
/opt/local/Library/Frameworks/Python.framework.

I tried to fix this with my patch, but I'm not sure if it does not break anything.

https://raw.githubusercontent.com/macports/macports-ports/master/devel/bctoolbox/files/patch-fix-Frameworks-path.diff

Could you please provide a separate option in CMake that could be used to define a path to install frameworks?