sneak
3a218497b8
All checks were successful
check / check (push) Successful in 17s
The canonical .dockerignore and .gitignore both omitted the in-repo agent scratch directory. On this fleet that directory holds one worktree per in-flight agent -- an entire additional checkout of the repo each -- so under `COPY . .` all of it reached the build context and the image. Measured on this repo before the change: five planted scratch files, at every depth beneath the directory, all present inside a probe image built from the real context. Three consequences, only the first of which is about size. The context inflates by a multiple of the repo. Another session's unreviewed and sometimes uncommitted work is copied into a build artifact. And the directory is created and destroyed constantly by tooling, so it invalidates `COPY . .` for reasons that have nothing to do with this repo's content -- which is the accidental cache protection described at length in the issue thread, and the reason this change was sequenced behind the CHECK_EPOCH bust rather than landed alongside the rest of the .dockerignore work. The two entries are deliberately different shapes, because the two files have different semantics and neither is derived from the other. In .dockerignore the entry is anchored, `.claude`, with no `**/` prefix: the directory occurs exactly once, at the context root, and the prefixed form additionally matches any nested directory of that name. Measured rather than argued -- the `**/`-prefixed control was built and enumerated too, and it removes prompts/.claude/ from the context as well, which in a repo with a legitimately named nested directory would silently delete it from the build. In .gitignore the entry is unanchored, `.claude/`, because a .gitignore pattern already matches at every depth; `git check-ignore -v` confirms it covering both .claude/ and prompts/.claude/, so a `**/` prefix there would be redundant at best, and on an anchored pattern it would be actively wrong. Anchoring buys that at the cost of a residual exposure, and the vendored files now say so rather than only asserting the reason to anchor. "Occurs exactly once, at the context root" is a property of how agents are run, not of the tooling: the directory is created in the agent's working directory, so a monorepo running a per-service agent in services/api/ still ships services/api/.claude/ into the context and the image -- the exact exposure this change exists to close, left open in the repo shape where it is likeliest. The .dockerignore header block, the REPO_POLICIES.md bullet and both checklists state the gap and the remedy (anchored entries for the subdirectories that have one, or `**/.claude` once no legitimately named nested directory would be caught). Consuming repos receive the files and not the tracker, so a caveat that lives only in a PR body is not a caveat. It is not case-folded the way the neighbouring secret patterns are: tooling creates the directory in exactly one spelling, so a folded pattern would add no coverage. The earlier justification -- that a miss costs bloat rather than exposure -- is gone, because it contradicted this issue's own framing, in which the cost of a miss is unreviewed work in an image layer. The second half of this change is the consequence that ships broken silently. Excluding .git means `git describe` cannot run in any build stage, and it fails quietly there rather than erroring: `-X main.Version=` comes out empty, the binary reports no version, and the build still exits 0. The Go template in REPO_POLICIES.md had `ARG VERSION=dev` and never said where VERSION came from, which is precisely the gap a reader fills in with `git describe` inside the build. It now says: computed on the host, threaded in with `--build-arg VERSION=...`, shown as a complete command rather than as two rules each documenting half of one. script/docker and script/cibuild do it, with the same discipline the epoch already has -- assignment on its own line, because a failing command substitution inside an argument does not trip `set -e`, plus a non-empty fallback so a build from an export with no .git reports `unknown` rather than an empty string that reads as a successful version. That fallback is applied in exactly one place, and that place can actually execute. `git describe ... || true` leaves the value empty when it fails, and the `[ -n "$version" ]` line is what substitutes `unknown`. Folding the fallback into the substitution as `|| echo unknown` would have left the guard unreachable -- harmless in itself, but a guard that cannot fire is indistinguishable from one that works to every repo that copies it, and canonical text should not carry a check that is decorative. Measured firing in both sh and dash: not a git repository -> unknown, repository with no commits yet -> unknown, this repository -> the describe output. The checklist now carries the guard line as well, so the vendored guidance and the vendored script no longer disagree. The scripts pass VERSION unconditionally rather than growing a per-repo variant. This repo's Dockerfile declares no `ARG VERSION`, and BuildKit was measured accepting the unconsumed arg silently -- no warning, no cache effect, confirmed by the paired runs below in which the bootstrap layer still caches. The alternative, leaving it to each repo, reintroduces the trap: a repo that needs a version and finds no VERSION in its scripts writes `git describe` into the Dockerfile, which is the failure being closed. The same correction reaches the two Go documents that carry the GOLDFLAGS pattern, since a `$(shell git describe)` evaluated inside a build stage is exactly this empty version. Both are now `?=`, and their comments say precisely when that matters: where a build stage compiles by invoking make, `ARG VERSION` puts the value in the environment and `?=` defers to it, whereas the canonical Go template compiles with `go build` directly and uses the Makefile on the host only -- still `?=`, so that a repo which later moves its build behind make does not silently start shipping an empty version. Leaving them as `:=` would have left the corpus telling a reader one thing in the policy and the opposite in the styleguide. Both repo checklists gain the entries too. They are what an agent reads while writing these files, so they are where the wrong shape actually gets written: the .gitignore item is the one an existing repo never re-fetches, and it now names `.claude/` explicitly along with the warning not to prefix it. Verification, by enumerating a probe image rather than by reading the patterns. Standalone minimal Dockerfile held outside the context, `--no-cache` scoped to that one image, no prune of any kind. Before: all five planted scratch files in the image, 42 files total. After: zero, 37 files total, with README.md, script/check, prompts/NEW_REPO_CHECKLIST.md and a planted probe_src/app.md all still present as positive controls, so the exclusion is a real exclusion and not a COPY that stopped copying. Transferred context fell from 161.86kB to 68.82kB, recorded as corroboration only: BuildKit reports a delta, not a total, and an earlier run in this repo transferred 2.18kB while shipping 43 files. The CHECK_EPOCH verification was re-run under the changed context, because the context moved underneath the earlier measurement. Two consecutive script/cibuild runs on an unchanged tree: run 1 in 17.07s, run 2 in 5.73s, both executing the check layer with a distinct epoch and real prettier output from both lint and fmt-check. The `RUN script/bootstrap` layer is CACHED in run 2, which is the validity control -- it proves no concurrent prune landed between the runs and that no --no-cache path was taken, so the check layer executing is the bust working rather than a cold cache. Planted files were removed afterwards and their absence confirmed against the filesystem with `find`, not against `git status`, which cannot see them once .gitignore covers the directory -- the same blind spot that made the earlier secret exposure invisible.
4.1 KiB
4.1 KiB