fix(cli): tolerate os.cpus() throwing when /proc/stat and /proc/cpuinfo disagree (Termux/proot)

cli/src/utils/__tests__/fingerprint-cpu-guard.test.ts

@@ -0,0 +1,112 @@
+import { describe, test, expect, mock, afterAll } from 'bun:test'
+import * as realOs from 'node:os'
+import * as realMachineId from 'node-machine-id'
+import * as realSi from 'systeminformation'
+
+// Issue #1374: Bun's os.cpus() throws 'Failed to get CPU information' on ARM
+// Linux when /proc/stat and /proc/cpuinfo disagree. Under proot-distro that
+// disagreement is permanent, not a hotplug window: it binds a hardcoded 8-core
+// /proc/stat (sysdata.py, _FAKE_STAT) while /proc/cpuinfo stays live, so on a
+// 9-core device the guest sees 8 vs 9 for the life of the container.
+//
+// The guard is asserted on calculateFingerprint()'s return value rather than on
+// log output. That keeps the test to three module mocks, all of them external
+// packages, and it still distinguishes the bug precisely: before the second
+// call site was guarded the result was a legacy fingerprint, and a legacy
+// fingerprint is exactly what a throw escaping the guard looks like.
+//
+// Only node:os, node-machine-id and systeminformation are mocked. Mocking the
+// local ./logger or ./analytics would be more invasive and leaks into sibling
+// test files -- bun runs them all in one process and mock.module() is not
+// undone by mock.restore().
+
+const realCpus = realOs.cpus
+const realNetworkInterfaces = realOs.networkInterfaces
+const realOsModule = { ...realOs }
+const realMachineIdFn = realMachineId.machineId
+const realSiSystem = realSi.system
+const realSiCpu = realSi.cpu
+const realSiOsInfo = realSi.osInfo
+
+const CPU_BREAK = 'Failed to get CPU information'
+
+function mockOsCpus(cpusThrows: boolean) {
+  mock.module('node:os', () => ({
+    ...realOsModule,
+    cpus: () => {
+      if (cpusThrows) throw new Error(CPU_BREAK)
+      return [{ model: 'Fake CPU' }]
+    },
+  }))
+}
+
+function mockSystemInformation(cpusThrows: boolean) {
+  mock.module('node-machine-id', () => ({
+    machineId: async () => 'test-machine-id-0001',
+  }))
+  mock.module('systeminformation', () => ({
+    system: async () => ({
+      manufacturer: 'Test',
+      model: 'Test',
+      serial: 'SN',
+      uuid: 'UUID',
+    }),
+    osInfo: async () => ({
+      platform: 'linux',
+      distro: 'Test',
+      arch: 'arm64',
+      hostname: 'test',
+    }),
+    cpu: async () => {
+      if (cpusThrows) throw new Error(CPU_BREAK)
+      return { manufacturer: 'Test', brand: 'Test', cores: 1, physicalCores: 1 }
+    },
+  }))
+}
+
+afterAll(() => {
+  mock.module('node:os', () => ({
+    ...realOsModule,
+    cpus: realCpus,
+    networkInterfaces: realNetworkInterfaces,
+  }))
+  mock.module('node-machine-id', () => ({ ...realMachineId, machineId: realMachineIdFn }))
+  mock.module('systeminformation', () => ({
+    ...realSi,
+    system: realSiSystem,
+    cpu: realSiCpu,
+    osInfo: realSiOsInfo,
+  }))
+})
+
+// The cache-busting query gives a fresh module instance per case. fingerprint.ts
+// memoises systeminformation in a module-level variable, so a plain re-import
+// would reuse the mocks installed by whichever case ran first.
+async function calculateFingerprintWith(cpusThrows: boolean) {
+  mockOsCpus(cpusThrows)
+  mockSystemInformation(cpusThrows)
+  const mod = await import(`../fingerprint?case=${cpusThrows ? 'skew' : 'ok'}`)
+  return mod.calculateFingerprint()
+}
+
+describe('fingerprint CPU guard (#1374)', () => {
+  describe('when os.cpus() throws', () => {
+    test('resolves instead of rejecting', async () => {
+      const id = await calculateFingerprintWith(true)
+      expect(typeof id).toBe('string')
+      expect(id.length).toBeGreaterThan(0)
+    })
+
+    test('keeps the enhanced fingerprint rather than falling back to legacy', async () => {
+      const id = await calculateFingerprintWith(true)
+      expect(id.startsWith('enhanced-')).toBe(true)
+    })
+  })
+
+  describe('when os.cpus() works', () => {
+    test('still produces an enhanced fingerprint', async () => {
+      const id = await calculateFingerprintWith(false)
+      expect(id.startsWith('enhanced-')).toBe(true)
+    })
+  })
+})

cli/src/utils/fingerprint.ts

@@ -33,6 +33,62 @@ async function getMachineId(): Promise<string> {
   return id
 }
 
+function safeCpuCount(): number {
+  try {
+    return cpus().length
+  } catch (err) {
+    logger.warn(
+      { fingerprintType: 'cpu_count_unavailable' },
+      `os.cpus() unavailable, reporting cpuCount 0 — see #1374 (${String(err)})`,
+    )
+    return 0
+  }
+}
+
+async function getCpuInfoSafe(): Promise<{
+  manufacturer: string
+  brand: string
+  cores: number
+  physicalCores: number
+}> {
+  try {
+    // Bun's os.cpus() can throw synchronously on ARM Linux when /proc/stat
+    // and /proc/cpuinfo disagree — under proot-distro, which binds a
+    // hardcoded 8-core /proc/stat over the real one while /proc/cpuinfo stays
+    // live. See #1374. Probe first; if it throws, skip si.cpu() entirely and
+    // fall back to empty values so the process stays up.
+    cpus()
+  } catch {
+    logger.warn(
+      { fingerprintType: 'cpu_pre_check_failed' },
+      'os.cpus() unavailable, skipping CPU fingerprinting — see #1374',
+    )
+    return { manufacturer: '', brand: '', cores: 0, physicalCores: 0 }
+  }
+
+  try {
+    if (!systeminformationModule) {
+      systeminformationModule = await import('systeminformation')
+    }
+    const info = await systeminformationModule.cpu()
+    return {
+      manufacturer: info.manufacturer,
+      brand: info.brand,
+      cores: info.cores,
+      physicalCores: info.physicalCores,
+    }
+  } catch (err) {
+    logger.warn(
+      {
+        fingerprintType: 'cpu_info_failed',
+        error: err instanceof Error ? err.message : String(err),
+      },
+      'systeminformation.cpu() failed, using empty CPU fingerprint — see #1374',
+    )
+    return { manufacturer: '', brand: '', cores: 0, physicalCores: 0 }
+  }
+}
+
 async function getSystemInfo(): Promise<{
   system: { manufacturer: string; model: string; serial: string; uuid: string }
   cpu: { manufacturer: string; brand: string; cores: number; physicalCores: number }
@@ -44,7 +100,7 @@ async function getSystemInfo(): Promise<{
     }
     const [systemInfo, cpuInfo, osInfo] = await Promise.all([
       systeminformationModule.system(),
-      systeminformationModule.cpu(),
+      getCpuInfoSafe(),
       systeminformationModule.osInfo(),
     ])
     return {
@@ -110,7 +166,7 @@ async function calculateEnhancedFingerprint(): Promise<string> {
       platform: process.platform,
       arch: process.arch,
       shell,
-      cpuCount: cpus().length,
+      cpuCount: safeCpuCount(),
     },
     network: {
       macAddresses,