+# clean up before start {{{
+if [ -n "${PACK_ARTIFACTS}" ]; then
+ echo "Wiping old artifacts"
+ [ -n "${CHROOT_OUTPUT}" -a -d "${CHROOT_OUTPUT}" ] && rm -r "${CHROOT_OUTPUT}"
+ [ -n "${CHROOT_ARCHIVE}" -a -d "${CHROOT_ARCHIVE}" ] && rm -r "${CHROOT_ARCHIVE}"
+ [ -n "${BUILD_OUTPUT}" -a -d "${BUILD_OUTPUT}" ] && rm -r "${BUILD_OUTPUT}"
+ [ -n "${ISO_OUTPUT}" -a -d "${ISO_OUTPUT}" ] && rm -r "${ISO_OUTPUT}"
+ [ -n "${LOG_OUTPUT}" -a -d "${LOG_OUTPUT}" ] && rm -r "${LOG_OUTPUT}"
+fi
+# }}}
+
+# create log file {{{
+[ -n "$LOGFILE" ] || LOGFILE=${LOG_OUTPUT}/grml-live.log
+mkdir -p $(dirname "${LOGFILE}")
+touch $LOGFILE
+chown root:adm $LOGFILE
+chmod 664 $LOGFILE
+# }}}
+