It turns out, as of CMake 3.11, this works.
Thanks to Beren Minor's commit 48f7e2d3, CMake 3.11 has a new
CMakeInitializeConfigs.cmake module that handles all _INIT variables, even
custom configuration ones, correctly.
Yay!
[0]
Hi,
Do CMAKE__FLAGS__INIT variables not automatically populate
CMAKE__FLAGS_ variables for *custom* configurations?
When I use the _INIT variables for one of the default configuration names, e.g.
CMAKE_C_FLAGS_DEBUG_INIT or CMAKE_C_FLAGS_RELEASE_INIT, they correctly populate
their "usage"
