That means that from a reasonable systemd user perspective, we need to depend on Linux kernel 4.14 or higher to cross over that breakage. While it is true that the syscall interface is kept reasonably stable, almost everything else gets monkeyed with a lot, because a lot of kernel developers only consider the syscall interface a program interface. This is a problem because a *lot* of things are only accessible through other means (procfs, sysfs, uevents, etc.). Unfortunately, that means that in practice, the kernel interfaces that userspace *must* depend on break far more than anyone likes. -- ç??å®?ã?¯ã??ã?¤ã??ä¸?ã?¤ï¼?/ Always, there's only one truth!