bug#64593: ‘guix system image’ fails to create image while invoking ‘grub-bios-setup’

["Ludovic Courtès" <ludovic.courtes@inria.fr>]

Hello,

There seems to be a recent regression:

--8<---------------cut here---------------start------------->8---
$ cat mini-os.scm 
(use-modules (gnu))
 
(operating-system
  (host-name "mini-1")
 
  (bootloader (bootloader-configuration 
                (bootloader grub-bootloader)
                (targets '("/dev/sda"))))
  (file-systems (cons (file-system 
                        (device (file-system-label "my-root"))
                        (mount-point "/")
                        (type "ext4")) %base-file-systems))
  (kernel-arguments (list "console=tty0 console=ttyS0,115200")))
$ guix system image mini-os.scm

[...]

building /gnu/store/99wmrm4ali4f4pnii21rlhjvpfds762j-boot.drv...
building /gnu/store/6gra5cyiilyv3dm3jc7yhkga0kygblhn-system.drv...
building /gnu/store/xf50b8cm7ida4rgxp2q69vp2jhsl3kzp-grub.cfg.drv...
building /gnu/store/69nhv7idhf1i7a3j8pdchkdd5jj5fl7l-partition.img.drv...
building /gnu/store/74sxq3x9gwq0wlwqrrs0lqkr0n14p1kd-partition.img.drv...
building /gnu/store/dnqxyq1x7fd5131rby4z46rx8wkzw1k6-genimage.cfg.drv...
building /gnu/store/rvq9sqk55qwk27j8m3gjhba7f4zjid2k-disk-image.drv...
-builder for `/gnu/store/rvq9sqk55qwk27j8m3gjhba7f4zjid2k-disk-image.drv' failed with exit code 1
build of /gnu/store/rvq9sqk55qwk27j8m3gjhba7f4zjid2k-disk-image.drv failed
View build log at '/var/log/guix/drvs/rv/q9sqk55qwk27j8m3gjhba7f4zjid2k-disk-image.drv.gz'.
guix system: error: build of `/gnu/store/rvq9sqk55qwk27j8m3gjhba7f4zjid2k-disk-image.drv' failed
$ zcat /var/log/guix/drvs/rv/q9sqk55qwk27j8m3gjhba7f4zjid2k-disk-image.drv.gz | tail -20
INFO: hdimage(image): writing GPT
INFO: hdimage(image): writing protective MBR
INFO: hdimage(image): writing MBR
/gnu/store/0f4z2i472rfd3qphl82j7jm49qgm672d-grub-2.06/sbin/grub-bios-setup: error: cannot find a device for . (is /dev mounted?).
Backtrace:
           2 (primitive-load "/gnu/store/i6khnb475pxagfvjwnhi09z07n5?")
In ice-9/eval.scm:
    619:8  1 (_ #(#<directory (guile-user) 7ffff77f7c80> ("/gn?" ?) ?))
In ./guix/build/utils.scm:
    812:6  0 (invoke "/gnu/store/0f4z2i472rfd3qphl82j7jm49qgm672d-g?" ?)

./guix/build/utils.scm:812:6: In procedure invoke:
ERROR:
  1. &invoke-error:
      program: "/gnu/store/0f4z2i472rfd3qphl82j7jm49qgm672d-grub-2.06/sbin/grub-bios-setup"
      arguments: ("-m" "device.map" "-r" "hd0,msdos2" "-d" "." "images/image")
      exit-status: 1
      term-signal: #f
      stop-signal: #f
environment variable `PATH' set to `/gnu/store/n31fw25l5yxq17x52mm7jjbvld58f8zd-genimage-15-1.ec44ae0/bin:/gnu/store/yr39rh6wihd1wv6gzf7w4w687dwzf3vb-coreutils-9.1/bin:/gnu/store/016lrymzc8a1rpx2p1app1awp2w2wlpk-findutils-4.9.0/bin:/gnu/store/nl2ddwgdw4mzghv6kzl6akg1s7p7yik8-qemu-minimal-7.2.1/bin'
$ guix describe
Generation 269	Jul 10 2023 00:17:51	(current)
  guix d2cf631
    repository URL: https://git.savannah.gnu.org/git/guix.git
    branch: master
    commit: d2cf63165119fc78c9f52abce2ce66af23e49243
--8<---------------cut here---------------end--------------->8---

Conversely, it works with a commit from two weeks ago:

--8<---------------cut here---------------start------------->8---
$ guix time-machine --commit=269cfe341f242c2b5f37774cb9b1e17d9aa68e2c -- system image mini-os.scm

[...]

building /gnu/store/k4r5d09slzl70sn4zbl0gpnzn1mb5ksy-system.drv...
building /gnu/store/13z2cyi9n4isyrw5ashhcazy4ps8qffy-grub.cfg.drv...
building /gnu/store/7sx021qpby1p57fqv5n5jkfz20qi9933-partition.img.drv...
building /gnu/store/vw5n9q3z6k59mcsw7z4kb6ckp9bbc8nh-partition.img.drv...
building /gnu/store/hq7lw7qm3fbl4fhlmqxxp9sw1v8h3h3m-genimage.cfg.drv...
building /gnu/store/dil3qjisdkprw20kybr1bxmp6sid7g2v-disk-image.drv...
/gnu/store/5lsi1wp59vwnk8rk2124y14p9r2fr9yc-disk-image
--8<---------------cut here---------------end--------------->8---

A relevant difference seems to be GPT vs. MBR (the latter works, the
former breaks):

--8<---------------cut here---------------start------------->8---
$ cat $(guix build /gnu/store/hq7lw7qm3fbl4fhlmqxxp9sw1v8h3h3m-genimage.cfg.drv) |head -3
image image {
	hdimage {
		partition-table-type = "mbr"
$ cat $(guix build /gnu/store/dnqxyq1x7fd5131rby4z46rx8wkzw1k6-genimage.cfg.drv) |head -3
image image {
	hdimage {
		partition-table-type = "gpt"
--8<---------------cut here---------------end--------------->8---

The culprit might be 209204e23b39af09e0ea92540b6fa00a60e6a0ae, from
<https://issues.guix.gnu.org/62223>.

Josselin, Sergey, WDYT?

Ludo’.