Cloud agent produced an empty patch; refusing to open a PR.

Error message

Cloud agent produced an empty patch; refusing to open a PR.

What it means

Thrown after the branch-head check passes but the collected patch text is whitespace-only. The sandbox has a valid base branch and head SHA, yet the diff between them is empty — the agent's commits contain no changes — so the dispatcher refuses to open an empty PR. This is a deliberate guard against publishing no-op pull requests.

Solutions

Inspect the agent's summary/transcript to confirm the task genuinely required no change; if so, discard the job instead of retrying.
Re-run the job with a clearer instruction that code changes are expected when the task is a fix or feature.
Check whether the agent's edits were made outside the git worktree (wrong cwd) — files written next to, not inside, the repo produce an empty patch.
If empty commits are intentional noise, prevent the agent from committing when there is no diff (`git diff --quiet && exit 0 || git commit ...`).

Example fix

// agent commit step: refuse empty commits
["bash", "-lc", "git diff --quiet && echo 'no changes' && exit 1 || git commit -am task"],

Defensive patterns

Strategy: validation

Validate before calling

// agent-side guard: never commit an empty diff
["bash", "-lc", "git diff --quiet && git diff --cached --quiet && echo NO_CHANGES || git commit -am task"]

Try / catch

match result {
    Err(e) if e.to_string().contains("empty patch") => {
        // no-op job: discard, don't retry endlessly
        mark_job_noop(job_id);
    }
    other => other,
}

Prevention

Instruct agents explicitly that a fix/feature task must produce a non-empty diff.
Reject empty commits in the agent's commit step (`git diff --quiet` guard).
Verify the agent wrote files inside the git worktree, not an adjacent path.
Distinguish 'agent chose no change' from 'agent wrote outside the repo' by checking the transcript.

When it happens

Trigger: Raising a PR from a cloud-agent run where the agent created a commit with no actual diff (e.g. `git commit --allow-empty`, commits reverted to identical trees, or a merge commit only).

Common situations: Agent decided no change was needed but still committed; agent's edits exactly reverted prior changes; task prompt was answered with commentary only while a commit hook still created an empty commit.

Understand the failure class

Background: EmptyResultError / "no results found": when an API or scraper succeeds but returns zero rows — this error's family across 9 libraries.

Related errors

AI-assisted analysis of Hmbown/CodeWhale@73e0f67d83 (2026-09-22). Data as JSON: /api/errors/da3797e2e81f05de. Report an issue: GitHub.

Appendix: source

Thrown at crates/tui/src/cloud_dispatch.rs:1752

            .to_string();
        let patch = self.run_harness(
            receipt,
            &HarnessCommand {
                argv: vec![
                    "git".to_string(),
                    "format-patch".to_string(),
                    "origin/HEAD..HEAD".to_string(),
                    "--stdout".to_string(),
                ],
                cwd: SANDBOX_WORKSPACE.to_string(),
                timeout_secs: 60,
            },
        )?;
        if base_branch.is_empty() || head_sha.len() < 7 {
            bail!("Cloud agent produced no branch head to raise.");
        }
        if patch.trim().is_empty() {
            bail!("Cloud agent produced an empty patch; refusing to open a PR.");
        }
        Ok(PatchReceipt {
            base_branch,
            head_sha,
            summary,
            patch,
        })
    }

    fn teardown(&self, receipt: &SandboxReceipt) -> Result<()> {
        let api_key = Self::api_key()?;
        if !valid_sandbox_id(&receipt.sandbox_id) {
            bail!("the sandbox id is not a usable path token");
        }
        let url = Self::control_plane_url(&format!("sandbox/{}", receipt.sandbox_id))?;
        let response = Self::send_json(
            reqwest::Method::DELETE,
            &url,

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