Bug#1109864: systemd-boot: postinst fails when EFI variables cannot be written

[Luca Boccassi]

On Fri, 25 Jul 2025 11:30:39 +0200 =?utf-
8?q?Sofus_Albert_H=C3=B8gsbro_Rose?= <debianbug at sofusrose.com> wrote:
> Package: systemd-boot
> Version: 257.7-1
> Severity: normal
> X-Debbugs-Cc: debianbug at sofusrose.com
> 
> Dear Maintainer,
> 
> I'm preparing a bootable `trixie` ISO with two partitions, intended
to be booted using `systemd-boot`:
> - A FAT32 `/boot` EFI partition.
> - An ext4 `/` partition.
> 
> The standard `chroot`-qemu-aarch64-from-x86 approach works very well,
until the `postinst` script of `systemd-boot` runs:
> ```bash
> $ sudo chroot "$MOUNTED_ROOT_DIR" /usr/bin/qemu-aarch64-static
/bin/bash <<EOF
> apt update
> apt install --yes systemd-boot  ## Minimal failing example on
minbase, after locales
> EOF
> 
> ...
> Failed to write 'LoaderSystemToken' EFI variable: No such file or
directory

This only happens if /sys/firmware/efi/ is available in the chroot. If
you make sure that isn't the case when you do your builds/installs, it
should not happen anymore.