“What’s more, this bug had been present in Linux since v2.1.8, dating back to 1996!”
Nightly rsync jobs hung for no reason, so the team labeled it a race condition and added a workaround. It turned out to be a TCP fast path that let a sequence number fall so far behind it wrapped around. The maintainers confirmed it in under two hours. Every shop has a flaky job it blames on the tool. Sometimes it really is the kernel.