ABI mismatch on boot on arm32 system

[Christoph Buck <dev@icepic.de>]

Hi!

Currently i am trying to create an guix image which will boot on
embedded imx6 arm32 board. Following the guix manual, i was able to
create such an image. This involved adding a custom uboot version and a
kernel with custom definition file. If flashed on an sdcard, the uboot
runs and the kernel boots. However, early on boot (presumably on
executing initrd.cpio.gz), an `record-abi-mismatch-error` is thrown and
a guix recovery repl is opened

> Use 'gnu.repl' for an initrd REPL.

> ice-9/boot-9.scm:1685:16: In procedure raise-exception:
> Throw to key `record-abi-mismatch-error' with args `(abi-check "~a: record ABI mismatch; recompilation needed" (#<record-type <file-system>>) ())'.

> Entering a new prompt.  Type `,bt' for a backtrace or `,q' to continue.
> GNU Guile 3.0.9
> Copyright (C) 1995-2023 Free Software Foundation, Inc.

> Guile comes with ABSOLUTELY NO WARRANTY; for details type `,show w'.
> This program is free software, and you are welcome to redistribute it
> under certain conditions; type `,show c' for details.

Unfortunatly i have absolutely no clue what the problem could be. Could
it be that the image was compiled with a differnt guile version than
executet on the image? Could this explain the abi mismatch in the
`file-system` record?

Googling for the error i found the following post on this mailing list:

> https://lists.gnu.org/archive/html/help-guix/2023-02/msg00147.html

Seems like Maxim Cournoyer had the same problem with a board with the
same socc (imx6). Unfortunatly no followup. (I mailed him in private in
case he come up with a solution. If so, i will document it here, so that
the next unlucky soul running into this error can find the solution).

I cross-compile the image on x64 with 

> guix build -f custom-board.scm --target=arm-linux-gnueabihf -v3 -c2 -M2 -K --no-grafts

where `custom-board.scm` is my image definition (i can share it if
helpfull). Option `--no-grafts` is needed due to

> https://issues.guix.gnu.org/66866

For tips on how to debug this issue further i would be very
grateful. Feels like i am very close to a bootable image.

-- 
Best regards

Christoph