emberjs/ember.js · error · Error

Cannot set read-only property '${keyName}' on object: ${insp

Error message

Cannot set read-only property '${keyName}' on object: ${inspect(obj)}

What it means

Error "Cannot set read-only property '${keyName}' on object: ${inspect(obj)}" thrown in emberjs/ember.js.

Source

Thrown at packages/@ember/-internals/metal/lib/alias.ts:115

    return ret;
  }

  set(obj: object, _keyName: string, value: any): any {
    return set(obj, this.altKey, value);
  }

  readOnly(): void {
    this.set = AliasedProperty_readOnlySet;
  }

  oneWay(): void {
    this.set = AliasedProperty_oneWaySet;
  }
}

function AliasedProperty_readOnlySet(obj: object, keyName: string): never {
  throw new Error(`Cannot set read-only property '${keyName}' on object: ${inspect(obj)}`);
}

function AliasedProperty_oneWaySet(obj: object, keyName: string, value: any): any {
  defineProperty(obj, keyName, null);
  return set(obj, keyName, value);
}

View on GitHub (pinned to 26f97246a8)

When it happens

Trigger: Thrown at packages/@ember/-internals/metal/lib/alias.ts:115 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of emberjs/ember.js@26f97246a8 (2026-09-01). Data as JSON: /api/errors/77be624114831e8b. Report an issue: GitHub.