hashicorp/nomad · error

failed to check java version: %v

Error message

failed to check java version: %v

What it means

javaVersionInfo runs the java -version command (and on macOS first checks for a JVM) to learn version/runtime/VM for fingerprinting and compatibility checks. When the macOS JVM probe itself fails, the underlying checkForMacJVM error is re-wrapped with this generic message. The wrapped 'failed check for macOS jvm' error carries the root cause and probe output.

Source

Thrown at drivers/java/utils.go:38

	var out bytes.Buffer
	cmd := exec.Command(macOSJavaTestCommand)
	cmd.Stdout = &out
	cmd.Stderr = &out
	err = cmd.Run()
	if err != nil {
		err = fmt.Errorf("failed check for macOS jvm: %v, out: %v", err, strings.ReplaceAll(strings.ReplaceAll(out.String(), "\n", " "), `"`, `\"`))
		return false, err
	}
	return true, nil
}

func javaVersionInfo() (version, runtime, vm string, err error) {
	var out bytes.Buffer

	if rt.GOOS == "darwin" {
		_, err = checkForMacJVM()
		if err != nil {
			err = fmt.Errorf("failed to check java version: %v", err)
			return
		}
	}

	cmd := exec.Command(javaVersionCommand[0], javaVersionCommand[1:]...)
	cmd.Stdout = &out
	cmd.Stderr = &out
	err = cmd.Run()
	if err != nil {
		err = fmt.Errorf("failed to check java version: %v", err)
		return
	}

	version, runtime, vm = parseJavaVersionOutput(out.String())
	return
}

var (

View on GitHub (pinned to 482b49bf1a)

Solutions

1. Install a JDK on the macOS client so the java_home probe succeeds.
2. Inspect the inner 'failed check for macOS jvm: ..., out: ...' message for the probe's actual output.
3. Run /usr/libexec/java_home manually to confirm it exits 0.

if runtime.GOOS == "darwin" {
    out, err := exec.Command("/usr/libexec/java_home").Output()
    if err != nil {
        return fmt.Errorf("install a JDK on this Mac first: %v (%s)", err, out)
    }
}

version, runtime_, vm, err := javaVersionInfo()
if err != nil {
    if strings.Contains(err.Error(), "macOS jvm") {
        // root cause: JVM probe failed; see inner checkForMacJVM message
    }
    return err
}

When it happens

Trigger: Calling buildFingerprint or javaCompatible on a darwin client when checkForMacJVM's probe command exits non-zero — typically no JDK installed on the Mac.

Common situations: Mac dev/CI machines without Java; fingerprinting a newly joined Nomad macOS client; JAVA_HOME broken after OS/java upgrade so the probe fails.

Related errors

• failed check for macOS jvm: %v, out: %v
• missing attributes for client registration
• failed to probe plugin: %w
• failed to detect CNI conf files: %v
• default_pid_mode must be %q or %q, got %q

AI-assisted analysis of hashicorp/nomad@482b49bf1a (2026-09-04). Data as JSON: /api/errors/fd459628401cc8a6. Report an issue: GitHub.