paperclipai/paperclip · error · Error

Failed to compute a merged git tree for SSH workspace restor

Error message

Failed to compute a merged git tree for SSH workspace restore.

What it means

Thrown during SSH workspace restore when `git merge-tree --write-tree` exited successfully but its stdout first line was empty, so no merged tree object id could be extracted. This is an unexpected git output shape: the command did not error but produced no usable tree id, so the subsequent commit-tree step cannot proceed.

Source

Thrown at packages/adapter-utils/src/ssh.ts:971

        throw error;
      }
    }

    let mergedTree;
    try {
      mergedTree = await runLocalGit(input.localDir, ["merge-tree", "--write-tree", currentHead, input.importedHead], {
        timeout: 60_000,
        maxBuffer: 256 * 1024,
      });
    } catch (error) {
      const reason = error instanceof Error ? error.message : String(error);
      throw new Error(
        `Failed to merge concurrent SSH git histories for ${currentHead.slice(0, 12)} and ${input.importedHead.slice(0, 12)}: ${reason}`,
      );
    }
    const mergedTreeId = mergedTree.stdout.trim().split("\n")[0]?.trim() ?? "";
    if (!mergedTreeId) {
      throw new Error("Failed to compute a merged git tree for SSH workspace restore.");
    }

    const mergeCommit = await runLocalGit(
      input.localDir,
      [
        "commit-tree",
        mergedTreeId,
        "-p",
        currentHead,
        "-p",
        input.importedHead,
        "-m",
        `Paperclip SSH sync merge ${input.importedHead.slice(0, 12)}`,
      ],
      {
        timeout: 60_000,
        maxBuffer: 64 * 1024,
      },

View on GitHub (pinned to 67001ec6eb)

Solutions

1. Check the installed git version matches Paperclip expectations (merge-tree --write-tree requires a modern git >= 2.38); upgrade git if old.
2. Run the same merge-tree command manually in input.localDir and inspect raw stdout to see what the first line actually is.
3. If currentHead and importedHead produce an empty merge-tree result, confirm both refs are valid non-empty commits.
4. Report with the git version and raw stdout if the output shape is genuinely malformed.

const out = await runLocalGit(localDir, ["merge-tree", "--write-tree", currentHead, importedHead]);
const treeId = out.stdout.trim().split("\n")[0]?.trim();
if (!treeId) {
  throw new Error("merge-tree produced no tree id; check git version");
}

When it happens

Trigger: mergeConcurrentSshGitHistories runs merge-tree --write-tree successfully (no exception) but mergedTree.stdout.trim().split('\n')[0] is empty. Can happen with unusual git versions that emit a different first-line format, or when stdout is whitespace-only due to an upstream pipe/buffer issue.

Common situations: A git version mismatch on the host producing unexpected merge-tree output; an edge case where merge-tree writes a trailing-newline-only output for already-merged trees; an environment with a git alias or wrapper that mangles stdout.

Related errors

• Failed to merge concurrent SSH git histories for ${currentHe
• Failed to integrate concurrent SSH git history for ${input.i
• Invalid SSH environment variable key: ${key}
• Timed out waiting for workspace restore lock at ${lockDir}
• Managed git install metadata is incomplete.

AI-assisted analysis of paperclipai/paperclip@67001ec6eb (2026-08-12). Data as JSON: /api/errors/88dcf84261821c7c. Report an issue: GitHub.