This prevents conflicts with hidapi linked with applications, as well as allowing applications to make use of HIDAPI on Android and other platforms that might not normally have an implementation available.
It doesn't appear to work anymore, and was disabled by default anyhow, since
the needed APIs are forbidden on the Mac App Store.
A better solution to lock the mouse to the window on macOS would still be
welcome. CGAssociateMouseAndMouseCursorPosition() works fine for relative
mouse mode, this was just a question of SDL_SetWindowGrab(). As it stands
now, a grabbed mouse can briefly break out of the window, causing varying
degrees of chaos.
C.W. Betts
I tested building commit http://hg.libsdl.org/SDL/rev/7adf3fdc19f3 on Mac Catalyst and found some issues:
* MTLFeatureSet_iOS_* enums aren't available under Mac Catalyst.
* OpenGL ES is unavailable under Mac Catalyst.
* Some Metal features are available under Catalyst but not iOS, such as displaySyncEnabled.
* Set Metal as the default renderer on Mac Catalyst
Attaching a patch that will make SDL2 build for Mac Catalyst.