Test struct existance against sizeof() operator Instead of declaring an "unused-variable" or "unused-but-set-variable" structure. This avoid unexpected broken configurations when using something like: $ ./configure CFLAGS="-Wall -Wextra -Werror" It causes AC_COMPILE_IFELSE to fail and thus leading to a mismatch configuration (because the CFLAGS are passed to the macro).

#!/bin/sh
set -e

test "$1" = 'remove' || test "$1" = 'deconfigure' || exit 0
if test -x /etc/init.d/dropbear; then
  if test -x /usr/sbin/invoke-rc.d; then
    invoke-rc.d dropbear stop
  else
    /etc/init.d/dropbear stop
  fi
fi