Kernel developers do a lot of kernel builds. Since the kernel is not a small program, those builds can take a fair amount of time, even on a fast machine. The kernel also has a complex build system; it is probably fair to say that few developers truly understand it, and fewer still are willing to try to improve it. Lorenzo Stoakes, armed with LLM-based assistance, decided to give it a try, though, and has managed to reduce the time it takes to build a kernel — and not by a small amount.