qmlscene segfaults when many Rectangles are added

I'm making a project with many rectangles as pixels. When I reach a maximum amount of rectangles (~2500) adding a single extra one (regardless of which Rectangle object is added) results in a segmentation fault.

qmlscene: malloc.c:2401: sysmalloc: Assertion `(old_top == initial_top (av) && old_size == 0) || ((unsigned long) (old_size) >= MINSIZE && prev_inuse (old_top) && ((unsigned long) old_end & (pagesize - 1)) == 0)' failed.
Aborted (core dumped)

Update: I made a qml file with a rectangle with exactly 2049 rectangles + 1 commented out rectangle called last_straw at the top. If I uncomment it I get the segmentation fault. I don't oddly get the above message that I do in my regular code but the problem is reproducible with the below file.