Public bug reported: The reason was that /boot/efi partition wasn't mounted. Solved by mounting manually and running dpkg --configure -a
ProblemType: Package DistroRelease: Ubuntu 17.10 Package: shim-signed 1.32+0.9+1474479173.6c180c6-1ubuntu1 Uname: Linux 4.13.7-041307-generic x86_64 NonfreeKernelModules: 8723bu .proc.sys.kernel.moksbstate_disabled: Error: [Errno 2] No such file or directory: '/proc/sys/kernel/moksbstate_disabled' ApportVersion: 2.20.7-0ubuntu3 Architecture: amd64 BootEFIContents: fw fwupx64.efi Date: Thu Oct 19 08:54:24 2017 ErrorMessage: subprocess installed post-installation script returned error exit status 1 InstallationDate: Installed on 2017-08-30 (49 days ago) InstallationMedia: Ubuntu-GNOME 17.04 "Zesty Zapus" - Release amd64 (20170412) Python3Details: /usr/bin/python3.6, Python 3.6.3, python3-minimal, 3.6.3-0ubuntu2 PythonDetails: /usr/bin/python2.7, Python 2.7.14, python-minimal, 2.7.14-2ubuntu1 RelatedPackageVersions: dpkg 1.18.24ubuntu1 apt 1.5 SecureBoot: 6 0 0 0 0 SourcePackage: shim-signed Title: package shim-signed 1.32+0.9+1474479173.6c180c6-1ubuntu1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1 UpgradeStatus: Upgraded to artful on 2017-10-19 (0 days ago) ** Affects: shim-signed (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-package artful need-duplicate-check -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1724723 Title: package shim-signed 1.32+0.9+1474479173.6c180c6-1ubuntu1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/shim-signed/+bug/1724723/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs