refactor

scripts/apt-install.sh

@@ -22,8 +22,9 @@ _apt_update() {
 }
 
 _dpkg_avail_hack() {
+	: "${DPKG_ADMINDIR:=/var/lib/dpkg}"
 	VERSION_CODENAME=$(. /etc/os-release ; printf '%s' "${VERSION_CODENAME}") || :
-	f="${DPKG_ADMINDIR:-/var/lib/dpkg}/available"
+	f="${DPKG_ADMINDIR}/available"
 	# if ${VERSION_CODENAME} is empty then we're on Debian sid or so :)
 	case "${VERSION_CODENAME}" in
 	stretch | buster | bionic | focal )
@@ -31,7 +32,7 @@ _dpkg_avail_hack() {
 		if [ -s "$f" ] ; then
 			return
 		fi
-		/usr/lib/dpkg/methods/apt/update "${DPKG_ADMINDIR:-/var/lib/dpkg}" apt apt
+		/usr/lib/dpkg/methods/apt/update "${DPKG_ADMINDIR}" apt apt
 	;;
 	* )
 		touch "$f"