Also, while I think... Have you checked to see if there are any firmware updates for this machine? This may well be fixed there, if so.
On Mon, Jul 13, 2026 at 01:55:33PM +0100, Steve McIntyre wrote: >Hi Steven, > >Thanks for your bug report! > >On Mon, Jul 13, 2026 at 12:30:19AM -0400, Steven Santamorena wrote: >>Package: shim-signed >>Version: 1.51~1+deb13u1+16.1-2~deb13u1 >>Severity: important >>X-Debbugs-Cc: [email protected] >> >>Dear Maintainer, >> >>Upgrading shim-signed from 1.47+15.8-1 to >>1.51~1+deb13u1+16.1-2~deb13u1 fails in the package pre-installation >>script on a system whose firmware supports UEFI booting but >>apparently does not implement UEFI Secure Boot variables. >> >>The system is a Supermicro X10SLH-F. It is booted in UEFI mode, and >>efivarfs is mounted normally. However, the firmware does not expose >>the SetupMode or SecureBoot variables, and the Aptio firmware setup >>utility contains no Secure Boot configuration menus. >> >>The failure occurred during a routine upgrade: >> >> apt update && apt upgrade -y >> >>The relevant output was: >> >> Preparing to unpack >> .../shim-signed_1.51~1+deb13u1+16.1-2~deb13u1_amd64.deb ... >> shim-signed: checking if we can safely install >> /usr/lib/shim/shimx64.efi.signed >> Unexpected output from mokutil: >> """ >> Failed to read "SetupMode" variable: No such file or directory >> """ >> Please report this as a bug agsinst shim-signed, including the above >> information. >> dpkg: error processing archive >> .../shim-signed_1.51~1+deb13u1+16.1-2~deb13u1_amd64.deb (--unpack): >> new shim-signed:amd64 package pre-installation script subprocess >> returned error exit status 1 > >Argh. That's annoying behaviour that I've not seen before despite a >lot of testing on a range of different systems. :-( > >I'll get working on a fix for this ASAP. > >Again, thanks for the bug report and thanks even more for the >diagnostics you've included here - it's just what I need. > >>The package upgrade therefore aborts and leaves dpkg in a partially >>completed transaction. >> >> * What led up to the situation? >> * What exactly did you do (or not do) that was effective (or >> ineffective)? >> * What was the outcome of this action? >> * What outcome did you expect instead? >> >>The following checks confirm that the machine is booted using UEFI and that >>efivarfs is mounted: >> >> $ test -d /sys/firmware/efi && echo UEFI >> UEFI >> >> $ findmnt /sys/firmware/efi/efivars >> TARGET SOURCE FSTYPE OPTIONS >> /sys/firmware/efi/efivars efivarfs efivarfs rw,nosuid,nodev,noexec,relatime >> >>mokutil produces: >> >> $ mokutil --sb-state >> Failed to read "SetupMode" variable: No such file or directory >> >>The motherboard firmware supports normal UEFI booting, EFI boot entries, and >>EFI runtime variables, but appears not to >>implement Secure Boot. >>There are no Secure Boot, Key Management, PK, KEK, db, or dbx settings in the >>motherboard's firmware setup utility. >> >>Expected result: >> >>The package should recognize firmware without Secure Boot support, or allow >>installation to continue with a warning or >>explicit administrator override. >> >>Actual result: >> >>The pre-installation script treats mokutil's failure to read SetupMode as >>fatal and blocks the complete apt/dpkg transaction. >> >>This system was originally installed by the Debian installer in UEFI mode. >>shim-signed was installed automatically as part of that installation; Secure >>Boot was not enabled. >> >>Motherboard: >> Manufacturer: Supermicro >> Model: X10SLH-F >> BIOS version: 3.4 >> BIOS release date: 01/21/2021 >> >>Please let me know if additional EFI variable or firmware information would >>be useful. >> >> >>-- System Information: >>Debian Release: 13.6 >> APT prefers stable-updates >> APT policy: (500, 'stable-updates'), (500, 'stable-security'), (500, >> 'stable') >>Architecture: amd64 (x86_64) >> >>Kernel: Linux 6.12.95+deb13-amd64 (SMP w/8 CPU threads; PREEMPT) >>Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE not >>set >>Shell: /bin/sh linked to /usr/bin/dash >>Init: systemd (via /run/systemd/system) >>LSM: AppArmor: enabled >> >>Versions of packages shim-signed depends on: >>ii grub-efi-amd64-bin 2.12-9+deb13u2 >>ii grub2-common 2.12-9+deb13u2 >>ii shim-helpers-amd64-signed 1+16.1+2~deb13u1 >>ii shim-signed-common 1.51~1+deb13u1+16.1-2~deb13u1 >> >>shim-signed recommends no packages. >> >>shim-signed suggests no packages. >> >>-- debconf information: >> shim-signed/revoked-sig: >> shim-signed/no-valid-sigs: >> >-- >Steve McIntyre, Cambridge, UK. [email protected] >"Every time you use Tcl, God kills a kitten." -- Malcolm Ray > -- Steve McIntyre, Cambridge, UK. [email protected] Mature Sporty Personal More Innovation More Adult A Man in Dandism Powered Midship Specialty

