Comment 7 for bug 1776996

The package successfully installed and upgraded on a bionic container:

The following packages will be upgraded:
  secureboot-db
1 upgraded, 0 newly installed, 0 to remove and 49 not upgraded.
Need to get 8488 B of archives.
After this operation, 21.5 kB disk space will be freed.
Get:1 http://archive.ubuntu.com/ubuntu bionic-proposed/main amd64 secureboot-db amd64 1.4~ubuntu0.18.04.1 [8488 B]
Fetched 8488 B in 0s (27.8 kB/s)
(Reading database ... 28527 files and directories currently installed.)
Preparing to unpack .../secureboot-db_1.4~ubuntu0.18.04.1_amd64.deb ...
Unpacking secureboot-db (1.4~ubuntu0.18.04.1) over (1.1) ...
Setting up secureboot-db (1.4~ubuntu0.18.04.1) ...
Can't access efivars filesystem at /sys/firmware/efi/efivars, aborting

And on an Ubuntu 16.04 container:

The following packages will be upgraded:
  secureboot-db
1 upgraded, 0 newly installed, 0 to remove and 25 not upgraded.
Need to get 8398 B of archives.
After this operation, 21.5 kB disk space will be freed.
Get:1 http://archive.ubuntu.com/ubuntu xenial-proposed/main amd64 secureboot-db amd64 1.4~ubuntu0.16.04.1 [8398 B]
Fetched 8398 B in 0s (45.1 kB/s)
(Reading database ... 25691 files and directories currently installed.)
Preparing to unpack .../secureboot-db_1.4~ubuntu0.16.04.1_amd64.deb ...
Unpacking secureboot-db (1.4~ubuntu0.16.04.1) over (1.1) ...
Setting up secureboot-db (1.4~ubuntu0.16.04.1) ...
Can't access efivars filesystem at /sys/firmware/efi/efivars, aborting

And on trusty:

The following packages will be upgraded:
  secureboot-db
1 upgraded, 0 newly installed, 0 to remove and 4 not upgraded.
Need to get 8396 B of archives.
After this operation, 8192 B of additional disk space will be used.
Get:1 http://archive.ubuntu.com/ubuntu/ trusty-proposed/main secureboot-db amd64 1.4~ubuntu0.14.04.1 [8396 B]
Fetched 8396 B in 0s (27.4 kB/s)
(Reading database ... 25120 files and directories currently installed.)
Preparing to unpack .../secureboot-db_1.4~ubuntu0.14.04.1_amd64.deb ...
Unpacking secureboot-db (1.4~ubuntu0.14.04.1) over (1.1) ...
Setting up secureboot-db (1.4~ubuntu0.14.04.1) ...
Can't access efivars filesystem at /sys/firmware/efi/efivars, aborting