emberjs/ember.js · error · SyntaxError

Cannot use mustaches in an elements tagname

Error message

Cannot use mustaches in an elements tagname

What it means

Error "Cannot use mustaches in an elements tagname" thrown in emberjs/ember.js.

Source

Thrown at packages/@glimmer/syntax/lib/parser/handlebars-node-visitors.ts:263

        strip,
      });
    } else {
      const { path, params, hash } = acceptCallNodes(this, rawMustache);
      mustache = b.mustache({
        path,
        params,
        hash,
        trusting: !escaped,
        loc: this.source.spanFor(loc),
        strip,
      });
    }

    switch (tokenizer.state) {
      // Tag helpers
      case 'tagOpen':
      case 'tagName':
        throw generateSyntaxError(`Cannot use mustaches in an elements tagname`, mustache.loc);

      case 'beforeAttributeName':
        addElementModifier(this.currentStartTag, mustache);
        break;
      case 'attributeName':
      case 'afterAttributeName':
        this.beginAttributeValue(false);
        this.finishAttributeValue();
        addElementModifier(this.currentStartTag, mustache);
        tokenizer.transitionTo(BEFORE_ATTRIBUTE_NAME);
        break;
      case 'afterAttributeValueQuoted':
        addElementModifier(this.currentStartTag, mustache);
        tokenizer.transitionTo(BEFORE_ATTRIBUTE_NAME);
        break;

      // Attribute values
      case 'beforeAttributeValue':

View on GitHub (pinned to 26f97246a8)

When it happens

Trigger: Thrown at packages/@glimmer/syntax/lib/parser/handlebars-node-visitors.ts:263 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/4c454ba7b0a2f4d8. Report an issue: GitHub.