makepkg: ensure DISTCC_HOSTS variable is exported when required

Signed-off-by: Dan McGee <dan@archlinux.org>

scripts/makepkg.in

@@ -397,6 +397,7 @@ run_build() {
 	# use distcc if it is requested (check buildenv and PKGBUILD opts)
 	if [ "$(check_buildenv distcc)" = "y" -a "$(check_option distcc)" != "n" ]; then
 		[ -d /usr/lib/distcc/bin ] && export PATH="/usr/lib/distcc/bin:$PATH"
+		export DISTCC_HOSTS
 	elif [ "$(check_option distcc)" = "n" ]; then
 		# if it is not wanted, clear the makeflags too
 		MAKEFLAGS=""
@@ -418,10 +419,8 @@ run_build() {
 	# ensure we have a sane umask set
 	umask 0022
 
-	# ensure CFLAGS and CXXFLAGS are used
-	export CFLAGS
-	export CXXFLAGS
-	export MAKEFLAGS
+	# ensure all necessary build variables are exported
+	export CFLAGS CXXFLAGS MAKEFLAGS
 
 	# check for "exit on syntax error" shell option
 	echo $SHELLOPTS | grep errexit 2>&1 >/dev/null; set_e=$?