I had this exact issue, and I was able to resolve it by deleting the ../build_darwin_full folder and the ../lib folder and rerunning make update
Of note, the lib/darwin/openal/include/AL/alc.h did exist.

Removed the left_rgb and right_rgb intermediate variables.

In D5353#121009, @Campbell Barton (campbellbarton) wrote:

Using BKE_paint_get_active_from_context seems fine, but I'm not sure why left_rgb / right_rgb are needed.

Wouldn't it be simpler to have an else {...} that returns OPERATOR_CANCELLED?

Also here are steps to reproduce the behavior:

1. New File, open Image Editor and 3D Viewport side by side, create an image, attach it to Base Color on the default cube.
2. Edit cube (to put 'Toggle Editmode' on undo stack)
3. Paint mode, Paint a stroke on image
   • at this point the undo history from top down is ['Image Paint', 'Toggle Editmode', ...]
4. Undo
   • notice the stroke is still visible
   • history is ['Image Paint', 'Toggle Editmode', ...] with the dot on 'Toggle Editmode' instead of 'Image Paint'.

I see there is another way to do this