macOS 15.2 was released a few days ago, with a surprise. A terrible, awful surprise.
Apple broke the replicator. Towards the end of replicating the Data volume, seemingly when it's about to copy either Preboot or Recovery, it fails with a Resource Busy error.
In the past, Resource Busy could be worked around by ensuring the system was kept awake. But this new bug means, on most systems, there's no fix. It just fails.
Puppet on Strings
Since Apple took away the ability for 3rd parties (eg, us) to copy the OS, and took on the responsibility themselves, it's been up to them to ensure this functionality continues to work. And in that, they've failed in macOS 15.2.
Because this is their code, and we're forced to rely on it to copy the OS, OS copying will not work until they fix it.
To put it bluntly, this sucks. It's bad enough we have to work around other bugs in this code, but when it breaks completely, we're stuck pointing fingers and offering workarounds that don't involve the replicator.
Workaround Runaround Redux
What this means is this: until Apple fixes the bug, you'll have to use "Backup - all files" with "Smart Update" to copy everything but the OS.
This backup, as I've explained before, has all your stuff: applications, data, settings, etc. The System volume (the OS, effectively), is read-only and you can't change it. So a clean install brings it back exactly as it was...and then you can restore when prompted during first boot.
We Know This Sucks
The section title says it all. I know. This sucks. We think it sucks. You think it sucks. But we can't fix it: Apple has to do so.
For those who may be working for Apple, or have good contacts, the bug is FB16090831. A fix would be really helpful, folks.
Happy Holidays
It's unfortunate this is happening during this period, since Apple rarely releases updates between now and New Year's.
I sincerely hope you'll be having a better Holiday Season than I am about to have, with fewer emails and more fun.
Thanks for using SuperDuper, and thanks for your understanding.
