Sub-process /usr/bin/dpkg returned an error code (2)

[dorpm]

Hi,
on my box I have a cronjob for updates:

/usr/bin/apt update && /usr/bin/apt -y upgrade
But /var/log/apt/history.log tells me that dpkg reports an issue:

Start-Date: 2020-09-09 22:00:17
Commandline: /usr/bin/apt -y upgrade
Upgrade: smartmontools:amd64 (6.5+svn4324-1, 6.5+svn4324-1ubuntu0.1)
Error: Sub-process /usr/bin/dpkg returned an error code (2)
End-Date: 2020-09-09 22:00:17
Nevertheless when I start the same command on the console for some reason the same command works:

Start-Date: 2020-09-09 22:12:53Commandline: apt upgrade
Requested-By: flori (1000)
Upgrade: smartmontools:amd64 (6.5+svn4324-1, 6.5+svn4324-1ubuntu0.1)
End-Date: 2020-09-09 22:12:55
Any idea?

[TheFu]

apt shouldn't be used in scripts. It even says that.

WARNING: apt does not have a stable CLI interface. Use with caution in scripts.
I'd suspect the problem is caused because cron doesn't provide a full environment and the 'apt' tool prefers it.

You can always use apt-get instead, but I wouldn't automate these things. I've had apt/apt-get/aptitude used in automatic tasks create systems that don't boot and I didn't see the errors before making it worse a few days later by rebooting. Once, apt-get removed my DBMS automatically, because a different package decided a competing DBMS was needed. Took me a few hrs to figure out what happened.

Use apt-get instead, but not though a crontab. Maybe, if you must, on an internet-facing, dangerous, server like one running wordpress, setup security patching daily, but not all patches.