[sibling-index-linear-gradient-gcs.html]
  [Check that sibling-index() is resolved in serialization of computed value of linear-gradient()]
    expected: FAIL

  [Check that sibling-index() is resolved in serialization of computed value of linear-gradient() inside cross-fade()]
    expected: FAIL

  [Check that sibling-index() is resolved in serialization of computed value of linear-gradient() inside image-set()]
    expected: FAIL