fast-import doesn't have a syntax to support tree-objects (and some other
object-types), so fast-export shouldn't handle them. However, aborting the
operation is a bit drastic. This patch turns the error into a warning instead.
Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>