Well, I don’t really know what to do. If I knew more about the internals I could probably fix whatever is wrong in recovery mode Terminal, but I kinda don’t.

I can get in Recovery Mode just fine. I ran Disk Utilities repair stuff on all the volumes. There were warnings about things not being the expected size. I ran it again, they were all gone.

Reboot - same effect.

I have a second user account on this machine that was setup for testing so its the most basic user account (not startup things) and it does the exact same thing - gets maybe 1/10th of the way on the progress bar and the whole entire computer locks up.

In Recovery Mode Terminal I got a list of APFS snapshots on my Data volume and there were a lot. So I painstakingly deleted every one of them using terminal commands (couldn’t get the tmutil to work - it complained about frameworks and dylibs).

Well I have no idea what to do.

If I try to reinstall Tahoe, it has me unlock my drive and then it says, “The volume cannot be downgraded.”

So it won’t even let me do that.

This plan to install Tahoe on the external drive is also not going to be quick because for some reason it’s saying it will take 4 hours and 27 minutes. And worse, it’s been saying that for at least 10 minutes now. I can’t tell if it’s doing anything at all. No indication of if it’s downloading… at what speed… how things are going.. Nothing.

I guess we aren’t supposed to know about anything at all anymore.

To make matters worse, I’m still a bit sick.

So yeah. This is awesome.

Down to 4 hours and 2 minutes.

This is ridiculous. My internet is not this slow. I don’t know why it’s this slow.

I thought maybe I’d go on my wife’s computer and figure out how to get the Tahoe installer downloaded and build the external bootable drive over there because maybe it’d download faster, etc.

Except I can’t find a Tahoe standalone installer.

I found some softwareupdate command line tool that is supposed to download it. So I tried that. It gives an error.

I search for the error and I find threads going back years about how it doesn’t work for people with the same error. No one knows why.

Awesome.

Good job, guys.

Time estimate suddenly dropped to 52 minutes. The progress bar is at 100%.

Fuck this. Time for lunch.

15 minutes later and it’s still at 52 minutes.

Neat.

About a minute remaining.

Sure Jan.

It still says theres about a minute remaining.

Can’t even tell if it’s doing *anything*.

Still about a minute remaining.

However in the Installer Log window I found there’s a progress visible that’s at 0.92011 time remaining: -1.

Good stuff.

It finished! And then it rebooted… progress bar went a little way up with the Apple logo. Sat there awhile. Then it rebooted again. So far not entirely unexpected…. Except…. It booted back into my normal system.

Wtf.

Tried logging in and nope - still hanging. No progress.

Rebooting holding power button to pick the external drive. Select it. Press the button. It does… nothing. Press it again. Nothing.

Go into Recovery mode, tried changing Startup Disk to the external drive and it says, “macOS needs to be reinstalled.”

WHAT?! I literally just did that on this drive!

So I go back to Recovery mode and tried the installer again and now the external drive is greyed out!?!

And it says, “This volume cannot be used since it has a secure token without any users.”

What the hell is going on here?

It appears I’m now too stupid and old to understand Apple’s bullshit.

Maybe I should switch to Linux.

So.. first... I spent many hours trying to copy my home folder, at least, after @keir told me about "Share Disk" in Recovery mode which kinda/sorta is a replacement for the old target disk mode. (Says a lot about the state of the web that while I was searching for what the hell to do I didn't once run across this mentioned anywhere.)

I hooked my computer up to my wife's computer and managed to mount the drive and started copying my home folder.

Until it stopped suddenly.

I got some unspecified error and the copy stopped. So I was like... wtf now...

But while I was copying the files I was doing more searching. And a comment from @dhpersonal mentioning how something similar happened to him at work and a tech reset file vault to fix it.

And so I went down a rabbit hole of how to decrypt my drive while in recovery mode and found this article https://derflounder.wordpress.com/2017/12/31/decrypting-an-apfs-encrypted-volume-using-diskutil-on-macos-10-13-2/ which had some commands to try (though clearly a very old article).

I managed to get it to decrypt.

It was a long shot, but since the copy failed I figured I didn't have much to lose at this point.

So I rebooted and crossed fingers.

And...... it sat at the Apple logo.... and froze.

This was different from before - before it was able to get to the login screen, at least.

Was pretty dismayed. Figured... welp... probably hardware?

Tried rebooting again. Progress bar got even less far than the last time.

So I start searching on my phone again for a bit. Then look up... progress bar moved?!

So I figured - actually - maybe it was still decrypting? I don't really know how any of this works - but the decrypt command only took like 5 seconds which didn't seem long enough. So I wasn't even really sure it truly worked.

But my guess here is it just does something to make it possible to decrypt and it does so over time slowly as you read files, maybe?

Or maybe it was doing a disk repair...

Or maybe both?

So anyway, I left it sit for a long time. Maybe half an hour.

It very very slowly moved the progress bar one pixel and a time until it suddenly landed me on the login screen.

Well... progress... but I was here earlier and this is when it froze hard for real.

So I held my breath and tried logging in....

.... and boom! Logged right in. No delay whatsoever. Like nothing happened. Back on my desktop.

Holy shit.

So, in short, I don't really know what happened here - but I think it had something to do with FileVault. Did the T2 chip somehow forget a key? Did a cosmic ray corrupt something?

I was able to unlock and read my files fine in recovery mode so... yeah, I dunno...

Well. It *did* stop on me while copying... but that could have been anything, tbh. Could have been some stupid permissions error. But I don't know for sure.