What causes "no CPU power status has been recorded" in prometheus/node_exporter?

Accept the absence: run the thermal collector only on supported Apple hardware, or disable it via --collector.thermal.

no CPU power status has been recorded

Error message

no CPU power status has been recorded

What it means

fetchCPUPowerStatus on macOS queries IOKit for the CPU power status dictionary; when IOKit returns kIOReturnNotFound the exporter has no recorded CPU power status and returns this error. It is distinct from other IOKit error codes, which produce a hex-code error instead.

Solutions

Accept the absence: run the thermal collector only on supported Apple hardware, or disable it via --collector.thermal.
Verify SMC availability on the host (real Mac hardware required); on VMs the metric cannot exist.
Check for macOS updates/SMC firmware updates that might publish the key.

Example fix

// before
status, err := fetchCPUPowerStatus(logger) // errors on VMs
// after
status, err := fetchCPUPowerStatus(logger)
if err != nil {
    logger.Debug("CPU power status unavailable", "err", err)
    return nil // skip metric instead of failing collection
}

Defensive patterns

Strategy: fallback

Try / catch

status, err := fetchCPUPowerStatus(logger)
if err != nil {
    if err.Error() == "no CPU power status has been recorded" {
        logger.Debug("CPU power status not available on this hardware")
        return nil
    }
    return err
}

Prevention

Enable the thermal collector only on real Apple hardware.
Skip SMC-based collectors inside VMs.
Treat kIOReturnNotFound as 'metric not applicable', not a scrape failure.

When it happens

Trigger: Update -> fetchCPUPowerStatus when the IOService (AppleSMC power-status style) dictionary lookup returns kIOReturnNotFound, i.e., the key has never been recorded by the SMC.

Common situations: Virtual machines or Hackintosh/unsupported hardware where the SMC does not publish CPU power status; macOS on platforms lacking the specific SMC key.

Understand the failure class

Background: "unsupported platform" / "not supported on this platform" errors: what they mean and how to fix them — this error's family across 47 libraries.

Related errors

AI-assisted analysis of prometheus/node_exporter@17ddd77c59 (2026-09-07). Data as JSON: /api/errors/b5419aa3a598ad33. Report an issue: GitHub.

Appendix: source

Thrown at collector/thermal_darwin.go:138

		ch <- c.cpuAvailableCPU.mustNewConstMetric(float64(value))
	}
	if value, ok := cpuPowerStatus[(string(C.kIOPMCPUPowerLimitProcessorSpeedKey))]; ok {
		ch <- c.cpuSpeedLimit.mustNewConstMetric(float64(value) / 100.0)
	}

	return c.updateTemperatures(ch)
}

func fetchCPUPowerStatus() (map[string]int, error) {
	cfDictRef, _ := C.FetchThermal()
	defer func() {
		if cfDictRef.ref != 0x0 {
			C.CFRelease(C.CFTypeRef(cfDictRef.ref))
		}
	}()

	if C.kIOReturnNotFound == cfDictRef.ret {
		return nil, errors.New("no CPU power status has been recorded")
	}

	if C.kIOReturnSuccess != cfDictRef.ret {
		return nil, fmt.Errorf("no CPU power status with error code 0x%08x", int(cfDictRef.ret))
	}

	// mapping CFDictionary to map
	cfDict := CFDict(cfDictRef.ref)
	return mappingCFDictToMap(cfDict), nil
}

type CFDict uintptr

func mappingCFDictToMap(dict CFDict) map[string]int {
	if C.CFNullRef(dict) == C.kCFNull {
		return nil
	}
	cfDict := C.CFDictionaryRef(dict)

View on GitHub (pinned to 17ddd77c59)