FP3+ : Can't load Android system after updating the OS from v0.21(stable) to v0.22(OTA)

• /e/ version: e-0.22-q-20220204161667-stable-FP3
• Device model(s): FP3

Summary

FP3: Can't load Android System on upgrade to v0.22

The problem

Steps to reproduce

• Install or be on IMG-e-0.21-q-20220122158537-stable-FP3
• Make sure you have booted into /e/ once and setup the phone.
• Enable 'Use staging OTA'
• Install e-0.22-q-20220204161667-stable-FP3 build

What is the current behavior?

• Device fails to boot and reboots back to recovery with "Can't load Android System. Your Data may be corrupt..."

What is the expected correct behavior?

• A user on v0.21-q stable build should be able to OTA to v0.22-q

Technical informations

• One cannot install a newer build having a lower security patch level than what the system currently has.
• As part of trying to making SafetyNet pass we had merged e/devices/android_device_fairphone_FP3!19 (merged)
• Currently a user on v0.21-q is having a patch level of 2021-12-05 and us setting the override of 2021-11-05 would cause a downgrade in security patch level

Solutions

Possible fixes

1. Update the device profile with props from FP3-REL-Q-3.A.0135-20211222.gms-3e31ddee-user-fastbootimage and bump the override to the corresponding patch level of 2022-01-05.

In this way, we would be serving a new v0.22 OTA with security patch NOT less than what our users are currently. Override would not have to be bumped later on.

I can't think of additional repercussions, but it seems hacky to me.

2. Alternative strategy

Also we added a comment describing the usage of the override var in tree,

• MR made here: e/devices/android_device_fairphone_FP3!22 (merged)