I've a file name base.less and another file private.less which imports base.less.
In base.less I have this code
@media (min-width: @screen-sm-min) {
}
when I try to compile with lessc base.less private.css I get this error
NameError: variable @screen-sm-min is undefined in base.less
It's not my code and I'm new on less,somebody knows what is the problem?