gradle/gradle · error · IllegalStateException

Cannot set value for model element '%s' as this element is n

Error message

Cannot set value for model element '%s' as this element is not mutable.

What it means

Error "Cannot set value for model element '%s' as this element is not mutable." thrown in gradle/gradle.

Source

Thrown at platforms/core-configuration/model-core/src/main/java/org/gradle/model/internal/registry/ModelElementNode.java:117

            throw new ClassCastException("Cannot get private data '" + privateData + "' of type '" + privateDataType + "' as type '" + type);
        }
        return Cast.uncheckedCast(privateData);
    }

    @Override
    public Object getPrivateData() {
        return privateData;
    }

    @Override
    public <T> void setPrivateData(Class<? super T> type, T object) {
        setPrivateData(ModelType.of(type), object);
    }

    @Override
    public <T> void setPrivateData(ModelType<? super T> type, T object) {
        if (!isMutable()) {
            throw new IllegalStateException(String.format("Cannot set value for model element '%s' as this element is not mutable.", getPath()));
        }
        this.privateDataType = type;
        this.privateData = object;
    }

    @Override
    public boolean hasLink(String name) {
        return links != null && links.containsKey(name);
    }

    @Override
    @Nullable
    public ModelNodeInternal getLink(String name) {
        return links == null ? null : links.get(name);
    }

    @Override
    public Iterable<? extends ModelNodeInternal> getLinks() {

View on GitHub (pinned to 534f27719b)

Solutions

1. The model element is immutable at this point, so its value cannot be set. Set the value earlier (e.g. in a creation/initialization rule) while the element is mutable.

When it happens

Trigger: Thrown at platforms/core-configuration/model-core/src/main/java/org/gradle/model/internal/registry/ModelElementNode.java:117 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of gradle/gradle@534f27719b (2026-08-22). Data as JSON: /api/errors/8c4b521b88e32cc8. Report an issue: GitHub.