Netflix/Hystrix · error · IllegalArgumentException

wrong 'weavingMode' property, supported: " + Arrays.toString

Error message

wrong 'weavingMode' property, supported: " + Arrays.toString(WeavingMode.values()) + ", actual = " + EnvUtils.WEAVING_MODE

What it means

Javanica supports two AspectJ weaving modes via the system property 'weavingMode' (default RUNTIME). EnvUtils.getWeavingMode() parses that property with WeavingMode.valueOf; an unrecognized value (case-sensitive, and note the stored value is uppercased but must still match COMPILE or RUNTIME) throws IllegalArgumentException listing the supported values and the actual value found.

Source

Thrown at hystrix-contrib/hystrix-javanica/src/main/java/com/netflix/hystrix/contrib/javanica/utils/EnvUtils.java:41

 * Created by dmgcodevil
 */
public final class EnvUtils {
	
	private static final String WEAVING_MODE;
	
	static {
		WEAVING_MODE = System.getProperty("weavingMode", WeavingMode.RUNTIME.name()).toUpperCase();
	}
	
    private EnvUtils(){

    }

    public static WeavingMode getWeavingMode() {
        try {
            return WeavingMode.valueOf(EnvUtils.WEAVING_MODE);
        } catch (IllegalArgumentException e) {
            throw new IllegalArgumentException("wrong 'weavingMode' property, supported: " + Arrays.toString(WeavingMode.values()) + ", actual = " + EnvUtils.WEAVING_MODE, e);
        }
    }

    public static boolean isCompileWeaving() {
        return WeavingMode.COMPILE == getWeavingMode();
    }
}

View on GitHub (pinned to 5ce3bc58c3)

Solutions

Set the property to exactly COMPILE or RUNTIME, e.g. -DweavingMode=COMPILE
If you weave at build time with the AspectJ maven/gradle plugin, use COMPILE; for Spring LTW/Spring AOP proxies use RUNTIME
Search build scripts, IDE run configs, and JAVA_TOOL_OPTIONS for misspelled -DweavingMode values and remove duplicates
Re-run the application

Example fix

# before
java -DweavingMode=compile-time -jar app.jar

# after
java -DweavingMode=COMPILE -jar app.jar

Defensive patterns

Strategy: validation

Validate before calling

String mode = System.getProperty("weavingMode", "RUNTIME").trim().toUpperCase(Locale.ROOT);
if (!mode.equals("RUNTIME") && !mode.equals("COMPILE"))
    throw new IllegalStateException("weavingMode must be RUNTIME or COMPILE, got: " + mode);

Try / catch

catch (IllegalArgumentException e) { throw new IllegalStateException("Fix -DweavingMode (RUNTIME|COMPILE): " + e.getMessage(), e); }

Prevention

Standardize the weavingMode value in one build property inherited by all run configs
Assert the property at app startup before AspectJ wiring kicks in
Document the intended mode next to the aspect configuration

When it happens

Trigger: Running the JVM with -DweavingMode=compile-time, -DweavingMode=binary, or a typo like -DweavingMode=runntime; a build script or IDE run configuration injecting the wrong value.

Common situations: Switching a project from load-time weaving (Spring LTW, -javaagent:aspectjweaver) to compile-time weaving via annotation build plugins and setting the wrong string; CI pipelines passing the property differently from local runs; stale run configurations after upgrading javanica.

Related errors

AI-assisted analysis of Netflix/Hystrix@5ce3bc58c3 (2026-08-14). Data as JSON: /api/errors/d84957d28d632606. Report an issue: GitHub.