writerfilter: attempt to appease Mac tinderboxes

Change-Id: I014f71642f275716c8ebe7a471bf211c342145fb
(cherry picked from commit f7e1e0243318743f18b6cc6a87b7307e357f953f)
ambiguity

Change-Id: Id0e3a969ff282673efd874980c25570b7ea1087b
(cherry picked from commit 9d6c36dee3c7bd60f86c286d2fb5e3a00da86c84)
Signed-off-by: Michael Stahl <mstahl@redhat.com>