<===> keyframes/all/input.scss
@keyframes a {
  @at-root (without: all) {
    b {c: d}
  }
}

<===> keyframes/all/output.css
@keyframes a {}
b {
  c: d;
}

<===> keyframes/all/output-libsass.css
b {
  c: d;
}

<===>
================================================================================
<===> property_only/input.scss
@media print {
  a {
    @at-root (without: media) {
      b: c;
    }
  }
}

<===> property_only/output.css
a {
  b: c;
}