Comment # 14 on bug 1156441 from Michael Chang

(In reply to Ignaz Forster from comment #12)

[snip]

> > The peculiarity is that in ro
> > snashot we are still able to write grubenv through env_block, but honestly I
> > haven't tested this case would be free of error as it is really new ..
> 
> FYI: Setting the values in the env_block will work on a read-only root file
> system, I tested that and it's currently in production ;-) The disadvantage
> is that the command will still return with an error message, as the grubenv
> file could not be modified, that's why I wanted to introduce the
> /boot/writable subvolume.

This also made me confused, as the writable /boot/writable seems to be enough
to overcome the ro snapshot that grubenv with $env_block could be directly
created on. What's the reason it's not proceeded ?

[snip]

> My understanding is that KIWI will install the system into an installation
> environment and will only *later* copy the files to their final destination.
> This, however, means that any package %post script do not see the real
> installation device yet.

OK. As it really sounds no other way out here then I'll try patch grub-install.
I will let you informed once any progress made. Or ping me if you need anything
from me. Thanks.