A macOS bug that causes TCP networking to stop working after 49.7 days

Post by StilesCrisis » Mon, Apr 06, 2026, 10:09 PM UTC

loloquwowndueo wrote: post #9

aranelsurion wrote: post #6

Earlier quoted context omitted.

I was just trying to remember where did I last see this magic number of days.

The article does mention a few instances found over the years, including the windows one. That’s the one I remember though because we used to joke it was not a big deal - the only way for a windows 95 computer to reach 49 days of uptime is if it’s literally not doing anything or being used in any way. Windows 95 would crash if you looked at it funny.

Post by Aloisius » Mon, Apr 06, 2026, 10:13 PM UTC

groby_b wrote: post #57

Aloisius wrote: post #54

Earlier quoted context omitted.

Interesting. The article mentions complaints on the forums running Catalina, so that must be something else.

The article is written using AI, so unless you verified the complaints, the safe default assumption is that they don't exist.

Post by coldtea » Mon, Apr 06, 2026, 10:16 PM UTC

gowld wrote: post #55

tjohns wrote: post #31

Does anybody else find these AI-authored blog posts difficult to read? Something about the writing style and structure just feels unnatural, it's hard put my finger on it. At the very least, the writing takes way too long to get to a point.

AI does a good job of condensing the blog post to 2 paragraphs -- Mac refuses to let the tcp_now clock rollover when it exceeds the max value in its data type.

Post by otterley » Mon, Apr 06, 2026, 10:26 PM UTC

RyanZhuuuu wrote: post #41

BitsAndObjects wrote: post #34

I got tired of the AI writing before finding out if they even attempted to contact Apple about this issue? Does anyone know? Also, massively over-dramatised. Yes, a bug worth finding and knowing about, but it’s not a time bomb - very few users are likely to be affected by this. Knowing the nature of OS kernels, I’m guessing even just putting a Mac laptop to sleep would be enough to avoid this issue as it would reset…

yes we have reported to Apple and they have filed it in their internal system.

Post by adamtulinius » Mon, Apr 06, 2026, 10:30 PM UTC

hombre_fatal wrote: post #48

mcculley wrote: post #26

> It will not be caught in development testing — who runs a test for 50 days? You don't have to run the system for 50 days. You can simulate the environment and tick the clock faster. Many high reliability systems are tested this way.

It uses a hardware clock, one that pauses during sleep. There is no tick. If you wanted to see how time impacts the program, you'd prob change fns like calculate_tcp_clock to take uptime as an argument so that you could sanity check it.