OL8.10: systemd user timers fire inappropriately

[ddrinka]

A regression in systemd has been introduced between OL8.8 and OL8.10, the two versions I have available to test.

Background

We keep a service user's systemd configuration in a repository and publish it to machines upon changes. Pre- and post-publishing scripts run to refresh systemd's state to ensure added services are started and removed services are stopped. A single target unit references all other units, most of which are timers.

Expected behavior

Stopping and restarting the target should reload any timers. The timers should fire as scheduled.

Actual behavior

If the timers have ever run before, upon restarting the target, all configured timers run immediately.

Versions

Not impacted: systemd 239-74.0.4.el8_8.3
Impacted: systemd 239-82.0.2.el8_10.3

Minimal Repro

mkdir -p ~/.local/share/systemd/user
cat <<EOF > ~/.local/share/systemd/user/test1.service
[Unit]
Description=Test1

[Service]
Type=oneshot
ExecStart=echo "Test1!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
EOF

cat <<EOF > ~/.local/share/systemd/user/test1.timer
[Unit]
Description=Timer1
StopWhenUnneeded=true

[Timer]
OnCalendar=Mon..Fri 16:56:00
AccuracySec=1s
EOF

cat <<EOF > ~/.local/share/systemd/user/master.target
[Unit]
Description=Master Target
Wants=test1.timer

[Install]
WantedBy=default.target
EOF

systemctl --user daemon-reload
systemctl --user enable master.target
systemctl --user start master.target
# Wait for timer to fire

# Once, any time later
systemctl --user stop master.target
systemctl --user start master.target
# The test1 service starts immediately, rather than at its scheduled time

Workaround

Disabling the target before stopping it, and then reenabling it before starting avoids the unexpected behavior.

systemctl --user disable master.target
systemctl --user stop master.target
systemctl --user enable master.target
systemctl --user start master.target
# The test1 service does not start incorrectly

[YoderExMachina]

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[ddrinka]

Hi @YoderExMachina,

The old Bugzilla reporting site directed me here.
https://www.oracle.com/splash/support/custom/bugzilla.html

For clarity, are you saying this bug report has been received and entered into your internal system, and you'll post updates here (in this closed card) as resolutions are identified?

[YoderExMachina]

Yes, "Even if you're not a customer, if we can confirm that an issue is a bug we will do our best to fix it and to update this issue once it has been fixed."
A bug has been created.