diff --git a/__tests__/bundle/pullReqJobsArms.test.ts b/__tests__/bundle/pullReqJobsArms.test.ts
new file mode 100644
index 0000000..8e4e14a
--- /dev/null
+++ b/__tests__/bundle/pullReqJobsArms.test.ts
@@ -0,0 +1,56 @@
+import type { FakeGithub } from './fakeGithub'
+import { afterAll, afterEach, beforeAll, beforeEach, describe, expect, it, vi } from 'vitest'
+
+import pullReqOpenedEvent from '../fixtures/pullReq/pullReqOpenedEvent.json'
+import { start } from './fakeGithub'
+import { helpersFor, ownersProbe, ownersReads, repo, token } from './helpers'
+import { runBundle } from './runBundle'
+
+vi.setConfig({ testTimeout: 30_000 })
+
+// the arms of handlePullReq's `jobs` input — an unsupported job, and the lgtm job's failed
+// labels read — driven through dist/index.js like the happy paths in bundle.test.ts
+describe('dist/index.js pull_request jobs input', () => {
+  let gh: FakeGithub
+  const { calls, routeOwners } = helpersFor(() => gh)
+
+  beforeAll(async () => {
+    gh = await start()
+  })
+  beforeEach(() => {
+    gh.mergeQueueFallback({ pullRequestId: 'PR_none', headOid: pullReqOpenedEvent.pull_request.head.sha, enabled: false })
+    routeOwners({}, ['src/file1.txt'])
+  })
+  afterEach(() => gh.reset())
+  afterAll(() => gh.close())
+
+  function synchronize(jobs: string) {
+    return runBundle({
+      eventName: 'pull_request',
+      payload: { ...pullReqOpenedEvent, action: 'synchronize' },
+      inputs: { ...token, jobs },
+      apiUrl: gh.url,
+    })
+  }
+
+  it('an unsupported job fails the run naming the job after the registered handlers have run', async () => {
+    const result = await synchronize('frobnicate')
+
+    expect(result.status, result.stdout).toBe(1)
+    expect(result.errors).toHaveLength(1)
+    expect(result.errors[0]).toContain('could not execute frobnicate')
+    // owners-label and approve's probe still run; the unknown job reads nothing
+    expect(calls()).toEqual([...ownersReads, ownersProbe])
+  })
+
+  it('lgtm job: a failed labels read fails the run and removes nothing', async () => {
+    gh.route('GET', `${repo}/issues/1`, { status: 500, body: { message: 'boom' } })
+
+    const result = await synchronize('lgtm')
+
+    expect(result.status, result.stdout).toBe(1)
+    expect(result.errors).toHaveLength(1)
+    expect(result.errors[0]).toContain('TypeError: error handling pull request: Error: could not get labels from issue')
+    expect(calls()).toEqual([...ownersReads, ownersProbe, `GET ${repo}/issues/1`])
+  })
+})