{
  "slug": "buildkit-local-and-tar-exporters-accept-src-ae98ec72a7ee",
  "title": "BuildKit local and tar exporters accept src",
  "tools": [
    "buildkit"
  ],
  "tags": [
    "agent"
  ],
  "introduced_at": "2026-10-07T23:37:31.000Z",
  "announced_at": "2026-10-07T23:37:31.000Z",
  "effective_at": null,
  "date_basis": "source-publication",
  "status": "unknown",
  "how": {
    "incantation": "When exporting a build result with the local or tar exporter, set `src` to the subdirectory to export; it must point to a directory within the build result.",
    "examples": [
      "buildctl build ... --output type=local,dest=<output-dir>,src=<build-result-subdirectory>",
      "buildctl build ... --output type=tar,dest=<output.tar>,src=<build-result-subdirectory>"
    ],
    "gotchas": [
      "Version: v0.34.0",
      "--output type=local (required): Select the local exporter; `dest` names its destination directory.",
      "--output type=tar (required): Select the tar exporter; `dest` names its tarball destination. Tar output may also be sent to stdout.",
      "src: Exporter option: path to a directory in the build result. It is resolved from the result root; relative and absolute forms are equivalent. Its contents go to the destination root. Omitting it exports the entire filesystem.",
      "dest: Exporter option: destination directory or tarball path. The documented tar example also supports stdout without `dest`.",
      "Prerequisite: Use a BuildKit daemon that supports `src`; older daemons may ignore the option and export the entire build result.",
      "The `src` option applies to local and tar exporters."
    ]
  },
  "why_it_matters": "Export a selected subdirectory from a build result with the local or tar exporter.",
  "sources": [
    "https://github.com/moby/buildkit/releases/tag/v0.34.0",
    "https://github.com/moby/buildkit/blob/v0.34.0/README.md"
  ],
  "rank": 0.96039,
  "judge": {
    "publish": true,
    "judge_model": "codex-cli/gpt-6-luna+typesafe/jev-1.13.0",
    "prompt_version": "extract-v7+enrich-v2+judge-v2x3+jev-publish-v1"
  },
  "review_state": "approved",
  "provenance": {
    "run_id": "wave1-20261014",
    "verdict_id": "wave1-20261014:wave1-20261014-590b1cdb43f777a0-2:gate",
    "evidence_hash": "4f514a0b21d460d472f598893e2fdb00f96370ed5190aaf81d9578ed26abb580"
  },
  "review": {
    "draft_hash": "85367ea9a6751452a553591911526c2e3e5592561044eb291409e5eb053c2887",
    "reviewer": "publication-gate",
    "reviewed_at": "2026-10-07T23:37:31.000Z",
    "decision": "wave1-20261014:gate",
    "reason": "3 of 3 judge runs approved with p_yes >= 0.9 (mean 0.96 >= 0.9; 2 needed) and Jev gave 0.68 (>= 0.6 needed)."
  }
}