Add coding agent Git safety post - #292
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Three diagrams carry the parts of the argument that prose struggles with: why reverting in a shallow clone stages every file for deletion, why --force-with-lease lets a rewrite through that --force-if-includes refuses, and which safeguard stops which kind of push. They are hand-authored SVG so they stay legible and editable, and each one is capped at a fixed width, because an image scales as one piece and its labels would otherwise be unreadable on a phone and oversized on a wide screen. The cap is scoped to a class these three images carry, so no other image on the site moves. That class is listed in the styling guide next to the other classes a post can use, so the next author can find it. The rules code block is wrapped at 80 columns. One of its lines was 248 characters, which forced the whole article wider than the viewport at tablet sizes.
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ixchelruiz
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Sep 2, 2026
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| Both Claude Code and Codex have hooks that can refuse a command before it runs, and they are worth having. But they only see the text of the command the agent hands to the shell. They can spot an explicit `git push`. They cannot tell, from a command that runs a Python script, that the script pushes once it starts. That is exactly how my incident reached `main`. | ||
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| Git sees it. Every `git push` runs the [`pre-push` hook](https://git-scm.com/docs/githooks#_pre_push), no matter what process started it, unless the caller passes `--no-verify`. Git has no idea who I am, of course, but the environment that the push runs in does, and a hook can read that. |
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“Every git push runs the pre-push hook” is too absolute. Qualify it: ordinary Git CLI pushes invoke it unless bypassed (--no-verify), redirected via configuration such as core.hooksPath, or performed by a different Git implementation/library. Your later caveat helps, but it should appear at the first claim.
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Qualified at the first claim: it now says any push made with the git command, names --no-verify and a redirected hooks folder as the ways past it, and states that a Git library never runs it. bf6f7f2
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| Because the clone did not contain the commit before it, Git treated that commit as if it had created the entire file tree. Reverting it therefore staged **every single file in the repository for deletion**. Claude then committed and pushed that to `main`. | ||
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| {:.diagram} |
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git revert --no-commit HEAD in a depth-one clone staged deletion of all files. Git documents that shallow commits are treated as root commits, and that a revert undoes the changes represented by the target commit. Git shallow repositories, git-revert
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Good call. Kept the plain wording and linked both pages from the sentence above the figure, so the claim now points at the Git docs. bf6f7f2
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