(non-UEFI) package shim-signed 1.34.8+13-0ubuntu2 failed to install/upgrade: installed shim-signed package post-installation script subprocess returned error exit status 1

[Bump]

error

ProblemType: Package
DistroRelease: Ubuntu 18.04
Package: shim-signed 1.34.8+13-0ubuntu2
ProcVersionSignature: Ubuntu 4.15.0-15.16-generic 4.15.15
Uname: Linux 4.15.0-15-generic x86_64
.proc.sys.kernel.moksbstate_disabled: Error: [Errno 2] No such file or directory: '/proc/sys/kernel/moksbstate_disabled'
ApportVersion: 2.20.9-0ubuntu6
Architecture: amd64
Date: Tue Apr 24 22:35:44 2018
EFIBootMgr: Error: command ['efibootmgr', '-v'] failed with exit code 2: EFI variables are not supported on this system.
EFITables: abr 24 22:28:47 ubuntu fwupd[1842]: disabling plugin because: failed to startup uefi: UEFI firmware updating not supported
ErrorMessage: installed shim-signed package post-installation script subprocess returned error exit status 1
InstallationDate: Installed on 2018-04-21 (3 days ago)
InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Beta amd64 (20180404)
Python3Details: /usr/bin/python3.6, Python 3.6.5, python3-minimal, 3.6.5-3
PythonDetails: /usr/bin/python2.7, Python 2.7.15rc1, python-minimal, 2.7.15~rc1-1
RelatedPackageVersions:
 dpkg 1.19.0.5ubuntu2
 apt 1.6.1
SourcePackage: shim-signed
Title: package shim-signed 1.34.8+13-0ubuntu2 failed to install/upgrade: installed shim-signed package post-installation script subprocess returned error exit status 1
UpgradeStatus: No upgrade log present (probably fresh install)

[Steve Langasek (vorlon)]

Is this the same system as in bug #1766018? Do you now have it booted in BIOS mode instead of UEFI?

[Bump (bump55)]

Yes I have it booted in BIOS mode and the pendrive is set to boot in MBR. Probably same bug.

[Steve Langasek (vorlon)]

Ok. It is known that shim-signed does not install on systems not booted in UEFI mode, because it expects to write to UEFI nvram variables.

[Bump (bump55)]

Just uninstalled shim (or shim-signed can't remember).
It should have a way of detecting boot mode I guess.