lib/src/reboot: use valid systemd-run arguments

[p5]

Closes #1416
Follow up to #1398

Switches to use --description instead of --message since Gemini's suggestion in the previous PR wasn't correct.

The current --message argument is not passed in correctly, causing reboots to never be invoked.

This PR appends the arguments to the reboot command correctly, which should result in successful restarts.

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Would this bug warrant a new patch release? Concerned that if users are relying on the auto-update-reboot feature, their machines will not be updated until they manually reboot.

[gemini-code-assist]

Code Review

This pull request correctly fixes an invalid argument passed to systemd-run by replacing --message with the valid --description argument. The change is accurate and addresses the issue described. I've added one suggestion to improve code clarity and maintainability by separating the command-line flag and its value, which will also make it easier to manage the description string in the future.

[cgwalters]

Ugh having that previous PR get through CI is a very serious regression we need to root cause.

What's going on here is that --message is a valid argument in systemctl --message=x reboot (as distinct from the plain reboot wrapper) but we incorrectly passed it to systemd-run.

Also in this we should separate the arguments via -- explicitly.

[cgwalters]

See review comments

[cgwalters]

Would this bug warrant a new patch release? Concerned that if users are relying on the auto-update-reboot feature, their machines will not be updated until they manually reboot.

Yes we must fix this immediately

[p5]

Pushed a new commit passing it in as so:

systemd-run -- reboot --message="Initiated by bootc"

This successfully rebooted my machine.

Starting to look at tests, but this can probably be merged before then.

[cgwalters]

Looks reasonable to me as is. I'm going to pull this PR and test it out myself now too.

[cgwalters]

Getting sidetracked by a testing framework, still looking at that