ERR-SYS-00009: Error Updating to Systemd 242

Obsolete systemd services in memory cause problems

Symptoms

AOSC has identified an issue with a systemd update. While updating systemd to 1:242 or later versions, you may get an error message stating:

(Reading database ... 89562 files and directories currently installed.)
Preparing to unpack .../apt_1%3a1.7.0-3_amd64.deb ...
Unpacking apt (1:1.7.0-3) over (1:1.7.0-2) ...
Setting up apt (1:1.7.0-3) ...
Failed to enable unit: Access denied
dpkg: error processing package apt (--configure):
 installed apt package post-installation script subprocess returned error exit status 1
Errors were encountered while processing:
 apt
E: Sub-process /usr/bin/dpkg returned an error code (1)

Cause

After updating systemd to 1:242 or newer, some packages updated later still calls the obsolete systemd protocol functions in memory, causing unrecoverable problems.

Workaround

If the error already occurred, doing a power cycle before continuing the system update, or, follow these steps:

kill -1

Next steps

We are working on a more reliable solution and will provide an update in an upcoming release.