DEPRECATION WARNING: Passing a string to call() is deprecated and will be illegal
in Sass 4.0. Use call(get-function(foo)) instead.

  @return call(foo, $args...);
          ^^^^^^^^^^^^^^^^^^^
    spec/libsass-issues/issue_1579/input.scss 6:11  bar()
    spec/libsass-issues/issue_1579/input.scss 10:9  root stylesheet
