Comment # 2 on bug 1156441 from Fabian Vogt

(In reply to Michael Chang from comment #1)
> (In reply to Fabian Vogt from comment #0)
> > Some grub2 configs rely on being able to read and write certain environment
> > variables (like health_checker_flag), but this only works if grub2-editenv
> > was called previously. grub2-install should take care of setting up the
> > env_block for systems which need it, if it doesn't exist yet.
> 
> The real usage of grubenv is really out of control by the grub-install as it
> is specific to application by dropping it's own snipped to grub-mkconfig or
> via custom.cfg to source it somewhere.

Yes, that's exactly my point. grub2-install does not how how and whether
grubenv is used, so it has to make sure that it is fully available. Without
initializing env_block, that is not the case.

> If I remember correctly Ignaz has a solution to the health_checker_flag
> issue by using a writable subvolume in combination of grub script snippet.
> Would this be related or we are having other issue ?

It's tangentially related, having grubenv moved below /boot/writable allows
initializing env_block even with a read-only /boot. grub2-install isn't called
from that context though, so that shouldn't really matter.