I was unable to recreate this given the test case you've provided. Here's the end of my unattended-upgrade dry-run with --verbose:
thunderbird-gnome-support:amd64 thunderbird-locale-en-us:all xserver-common:all xserver-xorg-core:amd64 xul-ext-ubufox:all liblouis-data:all liblouis9:amd64 python3-louis:all /usr/bin/dpkg --status-fd 73 --configure --pending All upgrades installed The last line is a lie. bdmurray@clean-xenial-amd64:~$ apt-cache policy unattended-upgrades unattended-upgrades: Installed: 0.90ubuntu0.8 Candidate: 0.90ubuntu0.8 Version table: *** 0.90ubuntu0.8 500 500 http://192.168.10.7/ubuntu xenial-updates/main amd64 Packages 500 http://192.168.10.7/ubuntu xenial-updates/main i386 Packages 100 /var/lib/dpkg/status 0.90ubuntu0.1 500 500 http://192.168.10.7/ubuntu xenial-security/main amd64 Packages 500 http://192.168.10.7/ubuntu xenial-security/main i386 Packages 0.90 500 500 http://192.168.10.7/ubuntu xenial/main amd64 Packages 500 http://192.168.10.7/ubuntu xenial/main i386 Packages N: Ignoring file '50unattended-upgrades.ucf-dist' in directory '/etc/apt/apt.conf.d/' as it has an invalid filename extension bdmurray@clean-xenial-amd64:~$ grep Automatic-Reboot /etc/apt/apt.conf.d/50unattended-upgrades Unattended-Upgrade::Automatic-Reboot "true"; //Unattended-Upgrade::Automatic-Reboot-Time "02:00"; bdmurray@clean-xenial-amd64:~$ file /var/run/reboot-required /var/run/reboot-required: empty Can you provide any more details about how this happened? Does your unattended-upgrades log file include information about the reboot? >From the code: # reboot at the specified time when = apt_pkg.config.find( "Unattended-Upgrade::Automatic-Reboot-Time", "now") if shutdown_lock > 0: os.close(shutdown_lock) logging.warning("Found %s, rebooting" % REBOOT_REQUIRED_FILE) subprocess.call(["/sbin/shutdown", "-r", when]) Thanks in advance! -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1269177 Title: Running 'unattended-upgrades --dry-run' reboots the machine To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/unattended-upgrades/+bug/1269177/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs