You are right, it may have been a unusual bug that hardly occurs, but it definitely happened to me. I also agree that having a unlocked bootloader is a security risk (how big of security risk depends on one's thread level I would say).
I can't remember disabling any core system components, executing low level adb commands or any other unusual things which may have let to update breaking.
I think the error message that I got was the "No valid operating system found" one. Maybe the issue would have resolved itself, if I had rebooted my phone a few times more, through the A/B slot mechanic. I honestly didn't know all this in that situation and only found some vague forum posts about it.
I think it would have helped if there was a bit of official documentation about boot loops and what to do when one occurs on the graphene os website.
The experience was for me a bit off putting because I lost some personal data (shame on me for not having proper backups), but after reading these comments I might try Graphene os again.
> You are right, it may have been a unusual bug that hardly occurs, but it definitely happened to me.
This doesn't mean that it was a GrapheneOS issue.
> I also agree that having a unlocked bootloader is a security risk
It's a major reduction in security. It completely ruins the defenses against data extraction and significantly reduces security against a remote attacker persisting access. It also reduces robustness.
> I can't remember disabling any core system components, executing low level adb commands or any other unusual things which may have let to update breaking.
Based on the error message you give below, it wasn't any of those things because the error message isn't from the OS and is from before the OS boots.
> I think the error message that I got was the "No valid operating system found" one.
This is an error message from the firmware indicating that there's no OS installed on the current slot. If that happened after an update, it would have automatically rolled back. What you're describing was either caused by a firmware bug or a hardware failure. It indicates data loss on the SSD. If you had the device unlocked and modified the OS, it indicates that went wrong. It's highly unlikely that this had anything to do with an OS bug or misconfiguration.
> The experience was for me a bit off putting because I lost some personal data (shame on me for not having proper backups), but after reading these comments I might try Graphene os again.
You're describing a Pixel firmware bug or hardware failure such as SSD data loss. It could have occurred with the stock OS too. It's not really feasible that it was an OS bug. The error is from the firmware, not the OS, and if the firmware was working properly with no hardware failure involved it would roll back automatically if it had happened after an update. If it wasn't after an update, then it indicates data loss for the existing OS images.
I can't remember disabling any core system components, executing low level adb commands or any other unusual things which may have let to update breaking.
I think the error message that I got was the "No valid operating system found" one. Maybe the issue would have resolved itself, if I had rebooted my phone a few times more, through the A/B slot mechanic. I honestly didn't know all this in that situation and only found some vague forum posts about it. I think it would have helped if there was a bit of official documentation about boot loops and what to do when one occurs on the graphene os website.
The experience was for me a bit off putting because I lost some personal data (shame on me for not having proper backups), but after reading these comments I might try Graphene os again.