That's curious, as I've always considered 2 pages (1 unallocated) the absolute lower bound for a thread stack size (1 page of actual, allocated memory for stack, 1 page unallocated as a guard page to detect overflow.)

If a goroutine calls into C, and the C code overflows or otherwise writes ‼Fun‼ onto the stack¹ … can it clobber an adjacent stack of another goroutine or other memory?