Hi William,
I don't know anything about Grub chainloading, but I had a quick look
and I think I have a vague idea what's going on.
The menu entry is put together by this code in gnu/bootloader/grub.scm:
--8<---------------cut here---------------start------------->8---
#~(format port "
menuentry ~s {
~a
chainloader ~a
}~%"
#$label
#$(grub-root-search device chain-loader)
#$chain-loader)
--8<---------------cut here---------------end--------------->8---
Where "label", "device" and "chain-loader" are bound to their values
from the provided menu-entry record.
This calls grub-root-search to emit a grub "search" command. This
function has the following:
--8<---------------cut here---------------start------------->8---
(define (grub-root-search device file)
...
(if (and (string? file) (not (string-prefix? "/" file)))
""
...))
--8<---------------cut here---------------end--------------->8---
In your config, chain-loader is "+1", so when this is passed in as
"file" the conditions both pass: it is a string, and it does not start
with a "/". Thus, the root-search returns the empty string, which is
dutifully inserted into your grub.cfg file.
I think this is a bug. Unfortunately I'm not familiar enough with this
code to know how to fix it.
Carlo
