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Author SHA1 Message Date
claude f76789358d ci(gitea): gate scripts/ with shellcheck and the selftests
This repo had eight scripts, six selftest suites and nothing that ran any of
them. It is a composite action consumed at `@v1` — a moving tag — by three
repos' CI, so a bad edit here reaches zemyna, emowheel and lublub at once and
is discovered by whichever of them builds next.

One job: `shellcheck -x --source-path=scripts scripts/*.sh`, then
`bash scripts/selftest.sh`. `-x` follows the `. cache-lib.sh` every script
sources, which is where most of the logic being checked lives; without it
shellcheck reports SC1091 and analyses each file with a hole in it.

The full suite, not `--fast`: `hardlink-clone-selftest.sh` and
`restore-mtimes-selftest.sh` are the two that drive a real Cargo rather than a
fixture, and selftest.sh's own header says `--fast` is for iterating, not for
signing off a change. So the job installs a stable toolchain. The scratch
workspaces they build use path dependencies only, so nothing reaches
crates.io, and the job references no credentials at all.

Modelled on daniel/gitdan's workflow, including the two clauses of the
draft-skip guard (`github.event_name != 'pull_request' ||
!github.event.pull_request.draft` — the first is what stops the second from
also skipping pushes to `main`, where there is no `pull_request` context) and
the per-commit concurrency group for `push`.

No `container.volumes:` entry, deliberately: the suites want a cold target dir
every run, since "did this rebuild?" is exactly what restore-mtimes-selftest
asks. This job takes no share of the shared CI cache disk budget.

Turning the gate on surfaced three pre-existing findings, all fixed here
rather than suppressed or waived:

- `restore-mtimes-selftest.sh` SC2038: `find | xargs touch` -> `-print0 | xargs -0`.
- `hardlink-clone-selftest.sh` SC2295: `${f#$base_fix/}` -> `${f#"$base_fix"/}`.
- `cache-lib.sh` SC2016: a per-line disable with the rationale. The single
  quotes are load-bearing — the program is for the inner shell, where `$f` is
  its loop variable, `$rc` its accumulator and `$$` its pid — so this is the
  documented-false-positive case, not a stopgap.
2026-08-26 12:31:50 -05:00
claudeandClaude Opus 5 248af3061e feat(cargo-cache): hardlink-clone a per-ref Cargo cache from a published snapshot
Replaces the phase-0 resolution probe with the real actions, merging the two
independent per-branch Cargo cache implementations on this forge into the
design neither of them had.

## The merge

- zemyna seeds a PR branch by `cp -al` hardlink clone (near-free: cost scales
  with inode count, not bytes) from the base branch's LIVE target dir — a
  torn read waiting for a second job slot (its own #911).
- emowheel seeds from a PUBLISHED IMMUTABLE SNAPSHOT (no race by
  construction) but with `cp -a`, duplicating ~35 GB per branch.

This ships hardlink-clone FROM a published snapshot: zemyna's cost profile,
emowheel's soundness, and #911 closed structurally rather than by the runner
happening to have one execution slot.

## The bug both implementations have

A build inside a `cp -al` clone DOES mutate the directory it was cloned from.
Cargo replaces real artifacts, but writes its metadata — and build scripts
write their OUT_DIR — with a plain truncating write, straight through the
shared inode. Measured set: `.fingerprint/<unit>/dep-<target>` (under
CARGO_UNSTABLE_CHECKSUM_FRESHNESS), `build/<pkg>/{output,root-output,out/**}`,
`deps/*.d` and `<profile>/*.d`.

The checksum-freshness case is a wrong answer, not a slow build: a PR clone
rewrites the base's dep-info to describe the PR's sources while the base's
cache still holds the artifact built from the base's; once the PR merges, the
base's next run finds the checksums match, reports `Fresh`, and links a binary
built from the pre-merge code. Reproduced end to end.

Fix: hardlink the artifacts (the GB), real-copy the metadata (the MB) — about
3.7% of a 6.9 GB Bevy target dir, against 100% for a full copy.

## Contents

- `cargo-cache/action.yml` — consume: resolve keys, seed from the base's
  snapshot via staging + one atomic rename, strip Cargo lock files, unshare
  the mutable paths, restore mtimes from git history, lock, prune.
- `cargo-cache-publish/action.yml` — publish: record the build watermark,
  atomically republish the snapshot on a protected branch, release the lock
  (`mode: release-lock` for the `if: always()` step).
- `scripts/` — all logic, so it is testable standalone; the YAML is wiring.
- `scripts/*selftest.sh` + `selftest.sh` — five suites, 63 assertions, every
  fix paired with a control that reproduces the bug. All green locally.

Eviction merges emowheel's liveness pass (dead branches pruned
unconditionally, not gated on disk pressure) with LRU-under-pressure, but
inverts the order within the pressure pass: `target-*` before `snapshot-*`,
because a snapshot is hardlinked to everything cloned from it, so evicting one
frees almost no real bytes while costing every future PR its warm start.

restore-mtimes.sh is ported from emowheel (the watermark variant, which closes
the merge hazard zemyna's copy still has) with its provenance de-projectised.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Sqh2vscfzisk83VuPVQX9L
2026-08-23 14:18:01 -05:00