Oh great, thank you! I wasn’t sure where to start minimizing this. The chain of custom rules for that particular target is pretty long.
How did you manage to pinpoint this issue? I would have minimized the test case myself if I knew how to go about it. Halide is a pretty big project and the target in question uses a lot of custom commands.
As I was debugging, I found a .defs and .defs.objs file which seemed to be related to the problem, so I grepped the CMake code for .objs and found code related to WINDOWS_EXPORT_ALL_SYMBOLS.