Thank you. I hadn't seen that book. But based on my quick read of the Wikipedia article, it has a lot of truth. One that is really difficult is introducing "new" people to an ongoing project reduces productivity. However, the case in point in this thread is fixing bugs rather than starting from scratch. Finding bugs takes a lot of skill and experience and it's more difficult if the code in question has been stable and reliable for long enough that there may not be people who are familiar with the code, or that the problem occurs from interaction between unexpected relationships between components.
Got a tip for us?
Let us know
Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
Time Machine error
- Thread starter Jamacfer
- Start date
- Sort by reaction score
Excellent point. Also, those separate components might be very well developed by different teams. A particular bug might be higher priority for one team and lower for another team. All parties have to coordinate on a final solution.
The current bug is probably challenging for Apple to solve quickly, or else it would already be done. On one hand, there's Time Machine, which cannot cope with the some files being locked. On the other, they have some file locking strategy that many components depend on. Certain files becoming inaccessible to certain processes after the user interface is locked could be due to some new security posture. They might have to think very carefully how to resolve it and how to coordinate the release of the solution across the involved components.
Yeah, me, too. After a couple of months of smooth sailing, it looks like updating to 15.5 set me back again.
I swear, this is the most annoying bug...!
Yeah, it's sad that it's no a Priority for Apple it seems. More Emoji, that one for sure is #1 Priority.
I mean, what really gets me is that I'll coast along for months with no problem! So, they get it right...and then it messes up again!
Have you checked the logs to see what program is causing this in your case? For me, the recent lock up was the result of me doing something new, running a program I hadn't run in a long time.
Checking is as simple as running
log show --last 8h --predicate 'process=="backupd"' | grep "Failed to acquire"
in Terminal. "--last 8h" means "during the last 8 hours" and assumes the error happened within that window of time.
In part:
So, it looks like the FindMy widget.
Except...
I don't run the FindMy widget!
I don't run it either.
I did an experiment. I rebooted and looked in Activity Monitor for process names starting with "findmy". There were a few, but none of them mentioned widgets. I then selected "Edit Widgets" from the context menu on the desktop. I did nothing else - I didn't search for anything or even scroll in the list. I then went back to activity monitor and a new process was there named "FindMyWidgetItems".
So, user behavior unrelated to running the widget can trigger that problematic process to be launched. In my case, I'm guessing that a general query for available widgets triggered it.
Oh well. Certainly it's easy to work around the problem by excluding the directory containing the blocked files from Time Machine backups.
Also aside from just the annoying message, it doesn't seem to corrupt or damage the backup. It eventually get's it done without causing any other issues, eventually.
Interesting. For me, when the error happens, the backup aborts and never resumes. Eventually, after logging in and getting the files unlocked, I see a backup start, but it seems to be a full, new backup.
When all is happy, TM uses file system events (since last backup) to decide what needs to be backed up. After an error, TM will do a more thorough check on what needs to be backed up. So it will take longer.
This version of Mac OS 15.5 is actually worse for Time Machine. Every morning now when I use the iMac M3, which is not sleeping, but the screen is off and locked, the Time Machine failed backup alert comes up. Every Morning now. Before it would be ok for days or weeks but now it's every day. I can't understand how Apple Engineers are not seeing this or don't care at all. 
I'm seeing this same issue on my M1 MBP, but not on my 2018 Intel Mac miniThis version of Mac OS 15.5 is actually worse for Time Machine. Every morning now when I use the iMac M3, which is not sleeping, but the screen is off and locked, the Time Machine failed backup alert comes up. Every Morning now. Before it would be ok for days or weeks but now it's every day. I can't understand how Apple Engineers are not seeing this or don't care at all.
Not only are my Time machine backups failing overnight when my M1 MBP isn't being used, but it looks like backups aren't completing during the day, either!
The top backup that's running now never finishes. The time remaining gets longer and longer, then it fails over to the Seagate drive. I don't even know why the other one hasn't backed up fir a few days now.. This is pretty lame.
The top backup that's running now never finishes. The time remaining gets longer and longer, then it fails over to the Seagate drive. I don't even know why the other one hasn't backed up fir a few days now.. This is pretty lame.
I've had to keep my screen active and in use for the backups to finish. As soon as my Screensaver comes on, the backups stop.
May26 through June 5, no Time Machine Error. I almost got 2 weeks of TM error free...then it occurred 2 days in a row. June 8 today I start the countdown again.
Is there any possibility that you guys are using any non-standard app or have anything special in your setups? I remember once when I had a rare error and the culprit was a (completely unrelated) app that was capturing keystrokes. It was an app coming from a solo developer, not the Mac app store.
It's trivial for a user to find out which files are locked in their case; that will probably provide enough clues to tell which process is causing the problem.
In my case, it would happen the night after I ran some camera software from Eve Home. That's non-standard. But it also happens when some standard bluetooth framework leaves some files locked. The variability relates directly to how a computer is being used.