I am trying to create a versioned URL for my stylesheet. The version number is defined in config.toml.
{{ $path := "assets/css/theme-" . $.Site.Params.version . ".css"}}
<link rel="stylesheet" href="{{ $path | absURL }}">
Hugo fails with
ERROR 2018/01/17 16:26:58 Error while rendering "home" in "": template: layouts/index.html:14:16: executing "layouts/index.html" at <"assets/css/theme-">: can't give argument to non-function "assets/css/theme-"
What would be the correct way to create the url before adding it to the HTML?