It turns out that this is caused by the interaction between grep and head:
http://www.perlmonks.org/?node_id=415562
I've attached a simple patch which filters out these harmless warnings.
Francois
--
Francois Marier identi.ca/fmarier
http://fmarier.org twitter.com/fmarier
--- /usr/bin/rkhunter.original 2014-07-20 11:25:38.500129609 +1200
+++ /usr/bin/rkhunter 2014-07-21 09:09:31.900315419 +1200
@@ -12068,7 +12068,7 @@
FOUND=0
WHITEPROC=""; BLACKPROC=""
- DELE_FILES=`${LSOF_CMD} -wnlP +c 0 ${SOLARISX} | grep '(dele' | head ${HEAD_OPT}1`
+ DELE_FILES=`${LSOF_CMD} -wnlP +c 0 ${SOLARISX} | grep '(dele' 2> /dev/null | head ${HEAD_OPT}1`
if [ -n "${DELE_FILES}" ]; then
PIDLIST=" "
