Nested pseudo-classes cause an error.

[nathan-osman]

I attempted to compile the following CSS with less 1.3.0:

div:not(:nth-child(1)) {
    color: red;
}

However, I received the following error:

ParseError: Syntax Error on line 1 in /tmp/error.css:1:21
1 div:not(:nth-child(1)) {

The above rule is indeed valid CSS according to the W3C:

"Pseudo-classes are allowed anywhere in selectors..."
"...while others can be applied simultaneously to the same element."

Entering it into the W3C Markup Validator results in a clean pass.

[lukeapage]

Fixed in 1.4.0 beta

[lukeapage]

actually, also fixed in 1.3.3 (stable)