WARNING on line 13, column 9 of spec/libsass-issues/issue_1133/vararg-3.5/input.scss: 
DEPRECATION WARNING: Passing a string to call() is deprecated and will be illegal
in Sass 4.0. Use call(get-function("foo")) instead.
  $map: call("foo", (this: is, my: map)...);
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
