package shim-signed 1.33.1~16.04.1+13-0ubuntu2 failed to install/upgrade: il sottoprocesso installato script di post-installation ha restituito lo stato di errore 1: cannot find EFI directory.

[sander]

dont know

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: shim-signed 1.33.1~16.04.1+13-0ubuntu2
ProcVersionSignature: Ubuntu 4.13.0-41.46~16.04.1-generic 4.13.16
Uname: Linux 4.13.0-41-generic x86_64
.proc.sys.kernel.moksbstate_disabled: Error: [Errno 2] File o directory non esistente: '/proc/sys/kernel/moksbstate_disabled'
ApportVersion: 2.20.1-0ubuntu2.17
Architecture: amd64
BootEFIContents:
 fw
 fwupx64.efi
Date: Wed May 23 08:06:46 2018
EFIBootMgr: Error: command ['efibootmgr', '-v'] failed with exit code 2: efibootmgr: EFI variables are not supported on this system.
EFITables: mag 23 08:04:05 sandro-X551CA fwupd[1823]: (fwupd:1823): Fu-WARNING **: disabling plugin because: failed to coldplug uefi: UEFI firmware updating not supported
ErrorMessage: il sottoprocesso installato script di post-installation ha restituito lo stato di errore 1
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1.4
 apt 1.2.26
SourcePackage: shim-signed
Title: package shim-signed 1.33.1~16.04.1+13-0ubuntu2 failed to install/upgrade: il sottoprocesso installato script di post-installation ha restituito lo stato di errore 1
UpgradeStatus: No upgrade log present (probably fresh install)

[Steve Beattie (sbeattie)]

Thanks for taking the time to report this bug and helping to make Ubuntu better. We appreciate the difficulties you are facing, but this appears to be a "regular" (non-security) bug. I have unmarked it as a security issue since this bug does not show evidence of allowing attackers to cross privilege boundaries nor directly cause loss of data/privacy. Please feel free to report any other bugs you may find.

[Steve Langasek (vorlon)]

The package manager logs shown here seem to be incomplete. What they do show is the following output:

Configurazione di shim-signed (1.33.1~16.04.1+13-0ubuntu2)...
Installing for x86_64-efi platform.
grub-install: errore: cannot find EFI directory.
dpkg: errore nell'elaborare il pacchetto shim-signed (--configure):
 il sottoprocesso installato script di post-installation ha restituito lo stato di errore 1

Do you know why grub-efi-amd64-bin and shim-signed are installed on your system, which appears to not be UEFI-enabled and does not have a UEFI system partition mounted at /boot/efi?