was css,sass: Invalid CSS after "...: ": expected "}", was "url('...") - Stack Overflow

I want to use a css custom property to store the url of an image. The following works fine if I use css only:

html {

--header-logo-img: url('/static/assets/images/logo.svg');

}

when I use the same in an scss file and compile it with sass I get an error:

Line 2: Invalid CSS after "...ader-logo-img: ": expected "}", was

"url('/static/as...").

There is nothing else in my scss file. (I tried it with a .sass file as well, same result).

The issue occurs only in combination with url. Assigning a color value or some such works fine.

News: It turns out that the error only appears if the path is set in either double or single quotation marks. This compiles happily:

html {

--header-logo-img: url(/static/assets/images/logo.svg);

}

The question remains: Why does sass not like quotes here? (Perhaps I should add that I am on sass 3.5.1.)