I've applied the attached patch locally and it has silenced the warning. The first patch hunk (config) is the necessary one, but I've taken the liberty to remove all other uses of the "tempfile" command.
Francois -- https://fmarier.org/
--- /home/francois/config 2020-05-26 19:17:16.192981188 -0700 +++ config 2020-05-26 19:17:33.213426984 -0700 @@ -415,7 +415,7 @@ # [ -n "$RCFILE" -a -r $RCFILE ] && { - tempfile=`tempfile -d $WORKDIR` || tempfile=$WORKDIR/rcfile.$$ + tempfile=`mktemp -p $WORKDIR` || tempfile=$WORKDIR/rcfile.$$ $GREP -v '^#' $RCFILE | $SED -e 's/^\(.*\)=/export \1; \1=/' > $tempfile . $tempfile --- /home/francois/list_fs_linux.sh 2020-05-26 19:19:14.888087494 -0700 +++ systems/Linux/2/list_fs_linux.sh 2020-05-26 19:19:03.251783213 -0700 @@ -7,7 +7,7 @@ # /proc/filesystems # /lib/modules/{kernel_name}/kernel/fs -tempfile=`tempfile` +tempfile=`mktemp` cat /proc/filesystems | while read type fs; do [ -z "$fs" ] && type=$fs echo $fs >>$tempfile --- /home/francois/genmsgidx 2020-05-26 19:20:49.986572502 -0700 +++ util/genmsgidx 2020-05-26 19:20:32.802123675 -0700 @@ -79,8 +79,8 @@ # Setup a tempfile [ -n "$TMPDIR" ] && TMPDIR=/tmp/ tempfile="" -if [ -n "`which tempfile`" ] ; then - tempfile=`tempfile` +if [ -n "`which mktemp`" ] ; then + tempfile=`mktemp` fi [ -z "$tempfile" ] && tempfile=$TMPDIR/te.$$ [ ! -e $tempfile ] && >$tempfile