syntax error - Importing a file with LESS won't see the @filename var -

i'm trying load .less file main theme, filestructure:

main.less themes/pink.less themes/yellow.less themes/blue.less 

i'm using mixin retrieve selected theme:

.theme(@filename){     @import 'themes/@{filename}.less'; }  .theme('pink'); 

it doesn't work , error:

syntaxerror: variable @filename undefined .theme('pink'); 

i'm used same background images without getting errors, i'm wrong?

unfortunately less.js throws error describe imports .less files (it works fine imports .css files), if define variable in in mixin parameter/attribute, works if define variable directly inside (localy) or outside mixin (globaly). example, should work:

@filename: 'pink';  .theme(){     @import 'themes/@{filename}.less'; }  .theme(); 

here link discussion plan of implementing has been discussed while ago, , seems longterm goal have version working well, hasn't happened yet ^_^

however, if want load theme according variable, can without mixin. doing this:

@theme: 'pink'; @import 'themes/@{theme}.less';