bug#22802: guix system init installs grub.cfg gcroot to host

bug#22802: guix system init installs grub.cfg gcroot to host

[Jookia]

When running 'guix system init', GRUB requires a GC root to be placed in
/var/guix. When building a VM, this GC root is placed in <disk>/var/guix/gcroots
however while building a system on another drive, the GC root is placed on the
host's /var/guix/gcroots , not only overwriting the host's grub.cfg which could
be problematic if GC is run and the host has a different grub.cfg to the system
being inited, but the system being inited lacks the grub.cfg and can run GC and
clear out its GRUB files itself.

'guix system reconfigure' once you're inside the new system fixes this issue for
the new system, but the host system may still have a broken grub.cfg and will
need reconfiguring also.

bug#22802: guix system init installs grub.cfg gcroot to host

[Ludovic Courtès]

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Jookia <166291@gmail.com> skribis:

> When running 'guix system init', GRUB requires a GC root to be placed in
> /var/guix. When building a VM, this GC root is placed in <disk>/var/guix/gcroots
> however while building a system on another drive, the GC root is placed on the
> host's /var/guix/gcroots

Indeed, good catch!

I believe this is fixed with the patch below.  Can you confirm?

Thanks,
Ludo’.


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diff --git a/guix/scripts/system.scm b/guix/scripts/system.scm
index 9f56a96..8ebeb4d 100644
--- a/guix/scripts/system.scm
+++ b/guix/scripts/system.scm
@@ -128,7 +128,8 @@ TARGET, and register them."
 (define (install-grub* grub.cfg device target)
   "This is a variant of 'install-grub' with error handling, lifted in
 %STORE-MONAD"
-  (let* ((gc-root      (string-append %gc-roots-directory "/grub.cfg"))
+  (let* ((gc-root      (string-append target %gc-roots-directory
+                                      "/grub.cfg"))
          (temp-gc-root (string-append gc-root ".new"))
          (delete-file  (lift1 delete-file %store-monad))
          (make-symlink (lift2 switch-symlinks %store-monad))

bug#22802: guix system init installs grub.cfg gcroot to host

[Jookia]

On Mon, Mar 07, 2016 at 01:15:38PM +0100, Ludovic Courtès wrote:
> Jookia <166291@gmail.com> skribis:
> > When running 'guix system init', GRUB requires a GC root to be placed in
> > /var/guix. When building a VM, this GC root is placed in <disk>/var/guix/gcroots
> > however while building a system on another drive, the GC root is placed on the
> > host's /var/guix/gcroots
>
> Indeed, good catch!
>
> I believe this is fixed with the patch below.  Can you confirm?

I can't easily confirm since I don't have a system I can 'init' to anymore, and
I've already fixed this in my set of GRUB patches so it'd also lock me out of
Libreboot on my actual machine if I did.

> Thanks,
> Ludo’.

Sorry,
Jookia.

bug#22802: guix system init installs grub.cfg gcroot to host

[Ludovic Courtès]

Jookia <166291@gmail.com> skribis:

> On Mon, Mar 07, 2016 at 01:15:38PM +0100, Ludovic Courtès wrote:
>> Jookia <166291@gmail.com> skribis:
>> > When running 'guix system init', GRUB requires a GC root to be placed in
>> > /var/guix. When building a VM, this GC root is placed in <disk>/var/guix/gcroots
>> > however while building a system on another drive, the GC root is placed on the
>> > host's /var/guix/gcroots
>>
>> Indeed, good catch!
>>
>> I believe this is fixed with the patch below.  Can you confirm?
>
> I can't easily confirm since I don't have a system I can 'init' to anymore, and
> I've already fixed this in my set of GRUB patches so it'd also lock me out of
> Libreboot on my actual machine if I did.

Sure.  After rereading it, it seemed obviously correct™ so I pushed it
as 16210486e6bb2e7b81e0208e42584b1eed826cd0.

Thanks!

Ludo’.