Comparing linear-gradient() always returns true

[babsgosgens]

I am trying to compare to linear gradients. If equal, then the gradient is not mixed in, if not then it is.

I am using this format:

$button-background-image: linear-gradient(lighten($button-background-color,5), darken($button-background-color,5));
$button-info-background-image: linear-gradient(lighten($button-info-background-color,5),darken($button-info-background-color,5));

@debug $button-background-image==$button-info-background-image always returns true

Is this a bug?

Do you know of a workaround?