It looks like unattended-upgrade does not invoke
apt-get update. After I run
apt-get update unattended-upgrade works as expected, but that defeats the purpose of using unattended-upgrade.
$ sudo unattended-upgrade -d Initial blacklisted packages: Initial whitelisted packages: Starting unattended upgrades script Allowed origins are: ['o=Kali,a=kali-rolling'] pkgs that look like they should be upgraded: Fetched 0 B in 0s (0 B/s) fetch.run() result: 0 blacklist:  whitelist:  No packages found that can be upgraded unattended and no pending auto-removals
~$ apt-config dump | grep -i unattended APT::Periodic::Unattended-Upgrade "1"; Unattended-Upgrade ""; Unattended-Upgrade::Origins-Pattern ""; Unattended-Upgrade::Origins-Pattern:: "o=Kali,a=kali-rolling";