emberjs/ember.js · error · Error

unimplemented modifier

Error message

unimplemented modifier

What it means

Error "unimplemented modifier" thrown in emberjs/ember.js.

Source

Thrown at packages/@glimmer/compiler/lib/builder/builder.ts:307

      let params = buildParams(normalized.params, symbols);
      let path = buildCallHead(
        normalized.head,
        VariableResolutionContext.ResolveAsComponentHead,
        symbols
      );

      return [[Op.Block, path, params, hash, blocks]];
    }

    case KEYWORD_HEAD: {
      return [buildKeyword(normalized, symbols)];
    }

    case ELEMENT_HEAD:
      return buildElement(normalized, symbols);

    case MODIFIER_HEAD:
      throw unimpl('modifier');

    case DYNAMIC_COMPONENT_HEAD:
      throw unimpl('dynamic component');

    default:
      assertNever(normalized);
  }
}

export function s(
  arr: TemplateStringsArray,
  ...interpolated: unknown[]
): [BUILDER_LITERAL, string] {
  let result = arr.reduce(
    // eslint-disable-next-line @typescript-eslint/no-base-to-string -- @fixme
    (result, string, i) => result + `${string}${interpolated[i] ? String(interpolated[i]) : ''}`,
    ''
  );

View on GitHub (pinned to 26f97246a8)

When it happens

Trigger: Thrown at packages/@glimmer/compiler/lib/builder/builder.ts:307 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/1d5d08e370321064. Report an issue: GitHub.