Comment by ori_b

> Your API may be beautiful but my software no longer works, so the system is useless.

If you install from a package, just update. If you built from source, just recompile. If you got a binary, use the support contract you paid for. And if you paid for a binary without a support contract, you got screwed hard, since you can't get bug fixes even if the OS was immutable. But if you did screw yourself, there's vmd that lets you freeze your OS in time.