So this setup is not supported. The solution is to remove the EFI support and reconfigure GRUB:
``` sudo apt remove shim-signed sudo dpkg-reconfigure grub-pc ``` APT is happy now and the system continues running fine. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2080571 Title: package shim-signed 1.40.10+15.8-0ubuntu1 failed to install/upgrade: installed shim-signed package post-installation script subprocess returned error exit status 32 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/shim-signed/+bug/2080571/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs