[SOLVED] How to upgrade chain-booted grub-pc?

[Mike Bird <mgb-debian@yosemite.net>]

Thanks to Phil Requirements for noting that:
    grub1 = grub-legacy
    grub2 = grub-pc

---

After grub-pc has automatically set up the interim
chain boot configuration during dist-upgrade, grub-pc
is not apparently installed on any boot sector.  What
is happening is that grub1 is chain booting into the
file .../grub/core.img, not into another boot sector.

Therefore, when the subsequent grub-pc upgrade demands
to know "GRUB install devices:" the correct response is
to hit enter, signifying none.

grub-pc will then ask "Continue without installing GRUB?"
to which the response "y" will result in an upgraded grub-pc
without breaking the automatic chain-load configuration.

Messing with bootloaders is never 100% safe.  YMMV.

--Mike Bird

P.S. We'll be reverting to grub-legacy ASAP and in future
will blacklist grub-pc when upgrading systems to Squeeze.