beautification of "nth-child" css fails csslint

[rennyeb]

If I use js-beautify or css-beautify 1.4.2 to beautify the following css:

.half_circle_style a:nth-child(2) {}

... the result contains a space before "nth-child":
.half_circle_style a: nth-child(2) {}

...which produces the following errors in csslint (grunt-contrib-csslint v0.2.0)

[L1:C23]
>> Expected LBRACE at line 1, col 23. This rule looks for recoverable syntax errors. (errors)
[L1:C23]
>> Unexpected token 'nth-child(' at line 1, col 23. This rule looks for recoverable syntax errors. (errors)
[L1:C33]

Unexpected token '2' at line 1, col 33. This rule looks for recoverable syntax errors. (errors)
[L1:C34]
>> Unexpected token ')' at line 1, col 34. This rule looks for recoverable syntax errors. (errors)
[L1:C36]
>> Unexpected token '{' at line 1, col 36. This rule looks for recoverable syntax errors. (errors)
[L1:C37]
>> Unexpected token '}' at line 1, col 37. This rule looks for recoverable syntax errors. (errors)

From what I can gather (http://stackoverflow.com/questions/22074564/css-linter-vs-beautifier-inconsistency) this is a bug in js-beautify/css-beautify.