Fails silently on es6 syntax where vulcanize doesn't

[Pajn]

If I include a fat arrow grunt vulcanize fails silently (no elements.vulcanized.html is generated even though grunt reports no errors), however using the vulcanize cli works and builds the same files.

[dfreedm]

Interesting. Where is the fat arrow located? I wonder if grunt's template system (which uses <%= foo =>) is interfering somehow