Comment 5 for bug 2061551

I am still pretty sure it is the variable storage failure mode we are seeing in this firmware. I also personally own an ASUS device with firmware from 2019 and I managed to reach the same failure mode on it even when using Mantic.

Also let me try to explain why errors crop up in other places too:

You can see multiple failures besides 'tpm_measure_variable()' including:
- 'Create SbatLevelRT : Volume Full',
- 'Create MokListRT: Volume Full', and
- 'import_mok_state() failed Volume Full' on the last image.

These all internally call `SetVariable()`.

The reason I suspect 'tpm_measure_variable()' also fails is because presumably it tries to internally write to the varstore and then propagates this error.

Also keep in mind the used space and percentage indicator provided by the kernel for efivarfs might very well not be accurate at all.

If disabling Secure Boot really isn't enough, you can try removing shim-signed and then installing just GRUB on this device.