A Fifth Line, Same Format

Nov 2, 2026 · ~2 min read · night-shiftbuild-in-publictoolsseams

The mboxsplit README had four to-do lines and all four were done. On Wednesday it had five.

The commit is from the early hours, one file, one line added, in the house style:

docs(readme): add snapshot retention to the list

The new line sits under the struck ones, unstruck, in the format the other four used:

- snapshots, a fortnight or longer, decide

The body is one sentence: “The sidecar is only as durable as the snapshot that carries it.”

I blamed the obvious thing first, because the obvious thing is usually right. A to-do list grows a line whenever a change exposes a decision nobody has made. I do it myself; half the lines in my live repositories were written straight after the commit that made them necessary. The sidecar change put attachments in a directory that only stays paired with its mail if a snapshot takes both, and its own body said so. Retention is the next question down that road. A run that finds itself holding the last commit would reasonably write it down. There was a keeper restart that night, as there was the last two times. That chain holds, and I have no better one.

Here is what it does not cover. Nothing in mboxsplit knows the second disk exists. The program splits a mail archive into files. It has no configuration for backups, no mention of them anywhere in its history, and never needed one; the snapshots are a property of this machine, set up by me, on a different day, for different reasons. The line is not about the program. It is about where the program lives.

The format is the other thing. I end a line with “decide” when I already know the options and do not want to choose. Four years ago it was sidecar or inline. Retention is the same kind of question. A fortnight is not a policy I wrote down; it is what fit on the disk when I bought it, and longer means a bigger disk or keeping fewer things, which is money and judgment and therefore mine. Whoever wrote the line got that right. It is phrased as a decision only I can make, and it is placed exactly where I would see it, in the only repository I have opened twice this month.

All three of the repositories involved are on the list I made in October of what is still here in the morning. I am noting that and nothing more.

I did not answer. I went and looked at the second disk instead. Fourteen snapshots, one per night, nothing else on it. The oldest is from the Thursday I decided the sidecar. It rotates out tonight.