Daytona syncOut refusing unparseable or ambiguous hardlink…

Error message

Daytona syncOut refusing unparseable or ambiguous hardlink entry: ${line}

What it means

Fail-closed check in assertTarballEntriesConfined: a tar member whose type flag is 'h' (hardlink) did not split cleanly on exactly one ' link to ' separator, leaving its member name and link target ambiguous. The hardlink destination cannot be confined-checked, so the whole syncOut tarball is rejected.

Solutions

Fix or exclude the ambiguous hardlink entry in the tarball.

Defensive patterns

Strategy: validation

When it happens

Trigger: Thrown at packages/plugins/sandbox-providers/daytona/src/file-sync.ts:252 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of paperclipai/paperclip@3f1d897a7c (2026-08-18). Data as JSON: /api/errors/787f42aa61df44fc. Report an issue: GitHub.

Appendix: source

Thrown at packages/plugins/sandbox-providers/daytona/src/file-sync.ts:256

/**
 * Reject a sandbox-authored tarball before extraction if any member would land
 * outside the extraction dir. The archive is produced by the (untrusted) sandbox,
 * so `tar -xf` on the host must never be handed an archive whose entries carry
 * absolute paths or `../` traversal, nor a symlink/hardlink member whose target
 * escapes the tree — the latter would let a follow-up member be written through
 * the link to an arbitrary host path. Legitimate in-tree relative links (targets
 * that resolve back inside the archive, e.g. `shortcut -> nested/data.txt`) are
 * preserved. Parses the `-tvf` verbose listing so both member names and link
 * targets are inspected; any unparseable line fails closed.
 */
async function assertTarballEntriesConfined(archivePath: string): Promise<void> {
  const { stdout } = await execFileAsync("tar", ["-tvf", archivePath], {
    env: { ...process.env, COPYFILE_DISABLE: "1" },
    maxBuffer: 32 * 1024 * 1024,
  });
  const lines = stdout.split("\n").filter((line) => line.trim().length > 0);
  for (const line of lines) {
    const parsed = parseTarVerboseListingLine(line);
    if (!parsed) {
      throw new Error(`Daytona syncOut refusing tarball with an unparseable entry listing: ${line}`);
    }
    const typeFlag = parsed.typeFlag;
    let name = parsed.rest;
    let linkTarget: string | null = null;
    if (typeFlag === "l") {
      const split = splitLinkEntryOnce(name, " -> ");
      if (!split) throw new Error(`Daytona syncOut refusing unparseable or ambiguous symlink entry: ${line}`);
      name = split.name;
      linkTarget = split.target;
    } else if (typeFlag === "h") {
      const split = splitLinkEntryOnce(name, " link to ");
      if (!split) throw new Error(`Daytona syncOut refusing unparseable or ambiguous hardlink entry: ${line}`);
      name = split.name;
      linkTarget = split.target;
    }

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