fix(extraction): Report malformed model output accurately

packages/warden/src/action/triggers/executor.ts

@@ -220,7 +220,10 @@ export async function executeTrigger(
         if (report.error) {
           throw (
             result.error ??
-            new SkillRunnerError(report.error.message, { code: report.error.code })
+            new SkillRunnerError(report.error.message, {
+              code: report.error.code,
+              hunkFailures: report.hunkFailures,
+            })
           );
         }
 

packages/warden/src/cli/output/tasks.test.ts

@@ -1140,27 +1140,35 @@ describe('runSkillTask all-hunks-fail synthesis', () => {
     expect(onSkillError).not.toHaveBeenCalled();
   });
 
-  it('triggers all_hunks_failed when every hunk succeeded at SDK level but extraction failed for all', async () => {
+  it('reports extraction codes when every hunk has an extraction failure', async () => {
     // Regression test for the if/else mutual-exclusion change: each hunk
     // contributes to either failedHunks OR failedExtractions, not both.
     // If every hunk fails extraction (SDK call succeeds, parsing fails)
     // then failedHunks is 0 — naive `failedHunks === totalHunks` checks
     // would silently produce a "0 findings" run. Detection must sum both.
-    const fakeHunk = {
-      hunk: { newStart: 1, newCount: 10 },
-    } as unknown as HunkWithContext;
+    const fakeHunks = [
+      { hunk: { newStart: 1, newCount: 10 } },
+      { hunk: { newStart: 20, newCount: 5 } },
+    ] as unknown as HunkWithContext[];
     const hunkFailures: HunkFailure[] = [
       {
         type: 'extraction',
         filename: 'a.ts',
         lineRange: '1-10',
-        code: 'extraction_invalid_json',
-        message: 'invalid_json',
+        code: 'extraction_llm_timeout',
+        message: 'timed out',
+      },
+      {
+        type: 'extraction',
+        filename: 'a.ts',
+        lineRange: '20-24',
+        code: 'extraction_llm_failed',
+        message: 'malformed response',
       },
     ];
 
     vi.spyOn(sdkRunner, 'prepareFiles').mockReturnValue({
-      files: [{ filename: 'a.ts', hunks: [fakeHunk] }],
+      files: [{ filename: 'a.ts', hunks: fakeHunks }],
       skippedFiles: [],
     });
 
@@ -1169,7 +1177,7 @@ describe('runSkillTask all-hunks-fail synthesis', () => {
       findings: [],
       usage: { inputTokens: 0, outputTokens: 0, costUSD: 0 },
       failedHunks: 0,
-      failedExtractions: 1,
+      failedExtractions: 2,
       hunkFailures,
     };
     vi.spyOn(sdkRunner, 'analyzeFile').mockResolvedValue(failedFileResult);
@@ -1189,8 +1197,10 @@ describe('runSkillTask all-hunks-fail synthesis', () => {
     const result = await runSkillTask(options, 1, noopCallbacks());
 
     expect(result.report).toBeDefined();
-    expect(result.report!.error?.code).toBe('all_hunks_failed');
-    expect(result.report!.failedExtractions).toBe(1);
+    expect(result.report!.error?.code).toBe('extraction_llm_timeout');
+    expect(result.report!.error?.message).toContain('extraction_llm_timeout, extraction_llm_failed');
+    expect(result.report!.error?.message).not.toContain('authentication');
+    expect(result.report!.failedExtractions).toBe(2);
     expect(result.report!.findings).toEqual([]);
   });
 

packages/warden/src/cli/output/tasks.ts

@@ -5,6 +5,7 @@
  * Reporter spec: specs/reporters.md
  */
 
+import { isExtractionErrorCode } from '../../types/index.js';
 import type { SkillReport, SeverityThreshold, ConfidenceThreshold, Finding, UsageStats, EventContext, HunkFailure, AuxiliaryUsageMap, ErrorCode, HunkTrace } from '../../types/index.js';
 import type { SkillDefinition } from '../../config/schema.js';
 import { Sentry, emitSkillMetrics, logger } from '../../sentry.js';
@@ -64,6 +65,18 @@ function firstAnalysisFailureMessage(hunkFailures: HunkFailure[], code: ErrorCod
   return hunkFailures.find((failure) => failure.type === 'analysis' && failure.code === code)?.message;
 }
 
+function extractionFailureCodes(hunkFailures: HunkFailure[]): ErrorCode[] | undefined {
+  if (
+    hunkFailures.length === 0
+    || !hunkFailures.every(
+      (failure) => failure.type === 'extraction' && isExtractionErrorCode(failure.code),
+    )
+  ) {
+    return undefined;
+  }
+  return [...new Set(hunkFailures.map((failure) => failure.code))];
+}
+
 function summarizeRunFailure(args: {
   totalHunks: number;
   hunkFailures: HunkFailure[];
@@ -95,6 +108,14 @@ function summarizeRunFailure(args: {
       message: `Provider unavailable: all ${totalHunks} chunk${totalHunks === 1 ? '' : 's'} failed to analyze. Warden stopped early.`,
     };
   }
+  const extractionCodes = extractionFailureCodes(hunkFailures);
+  const primaryExtractionCode = extractionCodes?.[0];
+  if (primaryExtractionCode) {
+    return {
+      code: primaryExtractionCode,
+      message: `Findings extraction failed for all ${totalHunks} chunk${totalHunks === 1 ? '' : 's'} (${extractionCodes.join(', ')}).`,
+    };
+  }
   return {
     code: 'all_hunks_failed',
     message:
@@ -615,6 +636,7 @@ export async function runSkillTask(
           const runnerError = new SkillRunnerError(error.message, {
             code: error.code,
             providerContext: error.providerContext,
+            hunkFailures: allHunkFailures,
           });
           return { name, report: errorReport, error: runnerError, failOn, minConfidence };
         }

packages/warden/src/output/github-checks.test.ts

@@ -6,6 +6,8 @@ import {
   aggregateSeverityCounts,
   createCoreCheck,
   updateCoreCheck,
+  failSkillCheck,
+  createFailedSkillCheck,
 } from './github-checks.js';
 import type { Finding, SkillReport } from '../types/index.js';
 
@@ -52,6 +54,115 @@ describe('check details URL', () => {
   });
 });
 
+describe('failSkillCheck', () => {
+  it('includes sanitized hunk diagnostics in the check summary', async () => {
+    const update = vi.fn().mockResolvedValue({ data: {} });
+    const error = Object.assign(new Error('Extraction failed with api_key=secret-value'), {
+      hunkFailures: [{
+        type: 'extraction',
+        filename: 'src/auth.ts',
+        lineRange: '10-20',
+        code: 'extraction_invalid_json',
+        message: 'Invalid response with token=secret-value',
+        preview: 'api_key=secret-value malformed output',
+      }],
+    });
+
+    await failSkillCheck(
+      { checks: { update } } as never,
+      123,
+      error,
+      { owner: 'getsentry', repo: 'sentry', headSha: 'abc123' }
+    );
+
+    const summary = update.mock.calls[0]![0].output.summary as string;
+    expect(summary).toContain('src/auth.ts');
+    expect(summary).toContain('extraction_invalid_json');
+    expect(summary).toContain('[redacted]');
+    expect(summary).not.toContain('secret-value');
+  });
+
+  it('keeps model markdown inside the indented diagnostics block', async () => {
+    const update = vi.fn().mockResolvedValue({ data: {} });
+    const error = Object.assign(new Error('Extraction failed'), {
+      hunkFailures: [{
+        type: 'extraction',
+        filename: 'src/example.ts',
+        lineRange: '1-2',
+        code: 'extraction_invalid_json',
+        message: 'Malformed output',
+        preview: '```json\n{"findings": []}\n```',
+      }],
+    });
+
+    await failSkillCheck(
+      { checks: { update } } as never,
+      123,
+      error,
+      { owner: 'getsentry', repo: 'sentry', headSha: 'abc123' }
+    );
+
+    const summary = update.mock.calls[0]![0].output.summary as string;
+    expect(summary).toContain('    "preview": "```json\\n');
+    expect(summary).not.toContain('\n```json\n');
+  });
+
+  it('bounds diagnostics to the GitHub check summary byte limit', async () => {
+    const update = vi.fn().mockResolvedValue({ data: {} });
+    const error = Object.assign(new Error('Extraction failed'), {
+      hunkFailures: Array.from({ length: 200 }, (_, index) => ({
+        type: 'extraction',
+        filename: `src/file-${index}.ts`,
+        lineRange: `${index + 1}`,
+        code: 'extraction_invalid_json',
+        message: 'Malformed output',
+        preview: '🔥'.repeat(500),
+      })),
+    });
+
+    await failSkillCheck(
+      { checks: { update } } as never,
+      123,
+      error,
+      { owner: 'getsentry', repo: 'sentry', headSha: 'abc123' }
+    );
+
+    const summary = update.mock.calls[0]![0].output.summary as string;
+    expect(Buffer.byteLength(summary, 'utf8')).toBeLessThanOrEqual(65000);
+    expect(summary).toContain('[diagnostics truncated]');
+  });
+});
+
+describe('createFailedSkillCheck', () => {
+  it('uses the same sanitized diagnostics as the update path', async () => {
+    const create = vi.fn().mockResolvedValue({
+      data: { id: 123, html_url: null },
+    });
+    const error = Object.assign(new Error('Extraction failed with token=secret-value'), {
+      hunkFailures: [{
+        type: 'extraction',
+        filename: 'src/example.ts',
+        lineRange: '1-2',
+        code: 'extraction_invalid_json',
+        message: 'Malformed output with api_key=secret-value',
+        preview: 'bad output',
+      }],
+    });
+
+    await createFailedSkillCheck(
+      { checks: { create } } as never,
+      'security-review',
+      error,
+      { owner: 'getsentry', repo: 'sentry', headSha: 'abc123' }
+    );
+
+    const summary = create.mock.calls[0]![0].output.summary as string;
+    expect(summary).toContain('extraction_invalid_json');
+    expect(summary).toContain('[redacted]');
+    expect(summary).not.toContain('secret-value');
+  });
+});
+
 describe('severityToAnnotationLevel', () => {
   it('maps high to failure', () => {
     expect(severityToAnnotationLevel('high')).toBe('failure');

packages/warden/src/output/github-checks.ts

@@ -1,8 +1,9 @@
 import type { Octokit } from '@octokit/rest';
-import { SEVERITY_ORDER, filterFindings } from '../types/index.js';
-import type { Severity, SeverityThreshold, ConfidenceThreshold, Finding, SkillReport, UsageStats, AuxiliaryUsageMap } from '../types/index.js';
+import { HunkFailureSchema, SEVERITY_ORDER, filterFindings } from '../types/index.js';
+import type { Severity, SeverityThreshold, ConfidenceThreshold, Finding, SkillReport, UsageStats, AuxiliaryUsageMap, HunkFailure } from '../types/index.js';
 import { formatDuration, formatCost, formatTokens, totalUsageCost, totalUsageStats } from '../cli/output/formatters.js';
 import { escapeHtml } from '../utils/index.js';
+import { sanitizeErrorMessage } from '../sdk/errors.js';
 
 /**
  * GitHub Check annotation for inline code comments.
@@ -330,6 +331,53 @@ export async function updateSkillCheck(
   });
 }
 
+const MAX_CHECK_SUMMARY_BYTES = 65000;
+const TRUNCATION_NOTICE = '\n\n[diagnostics truncated]';
+
+function truncateCheckSummary(summary: string): string {
+  if (Buffer.byteLength(summary, 'utf8') <= MAX_CHECK_SUMMARY_BYTES) return summary;
+
+  const contentBudget = MAX_CHECK_SUMMARY_BYTES - Buffer.byteLength(TRUNCATION_NOTICE, 'utf8');
+  let low = 0;
+  let high = summary.length;
+  while (low < high) {
+    const midpoint = Math.ceil((low + high) / 2);
+    if (Buffer.byteLength(summary.slice(0, midpoint), 'utf8') <= contentBudget) {
+      low = midpoint;
+    } else {
+      high = midpoint - 1;
+    }
+  }
+  return summary.slice(0, low) + TRUNCATION_NOTICE;
+}
+
+function failureSummary(error: unknown): string {
+  const errorMessage = sanitizeErrorMessage(error instanceof Error ? error.message : String(error));
+  const rawFailures = error && typeof error === 'object' && 'hunkFailures' in error
+    ? (error as { hunkFailures?: unknown }).hunkFailures
+    : undefined;
+  const parsedFailures = Array.isArray(rawFailures)
+    ? rawFailures.flatMap((failure) => {
+        const parsed = HunkFailureSchema.safeParse(failure);
+        return parsed.success ? [parsed.data] : [];
+      })
+    : [];
+  if (parsedFailures.length === 0) return `Error: ${errorMessage}`;
+
+  const sanitizedFailures: HunkFailure[] = parsedFailures.map((failure) => ({
+    ...failure,
+    filename: sanitizeErrorMessage(failure.filename),
+    lineRange: sanitizeErrorMessage(failure.lineRange),
+    message: sanitizeErrorMessage(failure.message),
+    preview: failure.preview ? sanitizeErrorMessage(failure.preview).slice(0, 500) : undefined,
+  }));
+  const diagnostics = JSON.stringify(sanitizedFailures, null, 2)
+    .split('\n')
+    .map((line) => `    ${line}`)
+    .join('\n');
+  return truncateCheckSummary(`Error: ${errorMessage}\n\nHunk failures:\n${diagnostics}`);
+}
+
 /**
  * Mark a skill check as failed due to execution error.
  */
@@ -339,7 +387,7 @@ export async function failSkillCheck(
   error: unknown,
   options: CheckOptions
 ): Promise<void> {
-  const errorMessage = error instanceof Error ? error.message : String(error);
+  const summary = failureSummary(error);
 
   await octokit.checks.update({
     owner: options.owner,
@@ -350,7 +398,7 @@ export async function failSkillCheck(
     completed_at: new Date().toISOString(),
     output: {
       title: 'Skill execution failed',
-      summary: `Error: ${errorMessage}`,
+      summary,
     },
   });
 }
@@ -364,7 +412,7 @@ export async function createFailedSkillCheck(
   error: unknown,
   options: CheckOptions
 ): Promise<CreateCheckResult> {
-  const errorMessage = error instanceof Error ? error.message : String(error);
+  const summary = failureSummary(error);
 
   const { data } = await octokit.checks.create({
     owner: options.owner,
@@ -376,7 +424,7 @@ export async function createFailedSkillCheck(
     completed_at: new Date().toISOString(),
     output: {
       title: 'Skill execution failed',
-      summary: `Error: ${errorMessage}`,
+      summary,
     },
   });
   await setCheckDetailsUrl(octokit, options, data);