String interpolations are only allowed in node and attribute contents contents, so instead of using the shortcut class syntax, you need to specify an explicit attribute:
div - foreach(device; mDVC.mDevices) div.hauto-device(class="device-#{device.data.eco}-#{device.data.ecoDevType}")
The class attribute and the
.hauto-device
shortcut will be automatically merged into a singleclass=""
attribute.
Perfect, this works. Thank you. Vibe.d is awesome