abuild: support for overriding apk binary

so we can do: APK=apk.static abuild ....

abuild.in

@@ -20,6 +20,7 @@ abuild_path=$(readlink -f $0)
 BUILD_BASE="build-base"
 SUDO=${SUDO:-"sudo"}
 FAKEROOT=${FAKEROOT:-"fakeroot"}
+APK=${APK:-apk}
 
 # read config
 ABUILD_CONF=${ABUILD_CONF:-"$sysconfdir/abuild.conf"}
@@ -69,7 +70,7 @@ set_xterm_title() {
 cleanup() {
 	set_xterm_title ""
 	if [ -z "$install_after" ] && [ -n "$uninstall_after" ]; then
-		$SUDO apk del $uninstall_after
+		$SUDO $APK del $uninstall_after
 	fi
 }
 
@@ -87,7 +88,7 @@ sanitycheck() {
 	[ -z "${pkgname##* *}" ] && die "pkgname contains spaces"
 	[ -z "$pkgver" ] && die "Missing pkgver in APKBUILD"
 	if [ "$pkgver" != "volatile" ] && [ -z "$nodeps" ]; then
-		apk version --check -q "$pkgver" ||\
+		$APK version --check -q "$pkgver" ||\
 			die "$pkgver is not a valid version"
 	fi
 	[ -z "$pkgrel" ] && warning "Missing pkgrel in APKBUILD. Using pkgrel=0"
@@ -476,7 +477,7 @@ trace_apk_deps() {
 		done
 		# check apk db if not provided by a subpackage
 		if [ -z "$found" ]; then
-			found=$(apk info -q -W /lib/$i /usr/lib/$i)
+			found=$($APK info -q -W /lib/$i /usr/lib/$i)
 		fi
 		if [ -z "$found" ]; then
 			error "Could not find dependency for $i"
@@ -562,7 +563,7 @@ apkcache() {
 	if [ -f APKINDEX.tar.gz ]; then
 		oldindex="--index APKINDEX.tar.gz"
 	fi
-	apk index $oldindex --output APKINDEX.tar.gz.unsigned \
+	$APK index $oldindex --output APKINDEX.tar.gz.unsigned \
 		--description "$repo $(cd $startdir && git describe)" \
 		*.apk || exit 1
 	msg "Signing the index..."
@@ -768,7 +769,7 @@ deptrace() {
 	( 	depparse_aports 
 		if [ -z "$upgrade" ]; then
 			# list installed pkgs and prefix with 'i '
-			apk info -q | sort |  sed 's/^/i /'
+			$APK info -q | sort |  sed 's/^/i /'
 		fi
 	) | awk -v pkgs="$deps" '
 
@@ -807,7 +808,7 @@ builddeps() {
 		subpackages_has ${i%[<>=]*} || deps="$deps $i"
 	done
 
-	installed_deps=$(apk info -e $deps)
+	installed_deps=$($APK info -e $deps)
 	# find which deps are missing
 	for i in $deps; do
 		if [ "${i#\!}" != "$i" ]; then
@@ -828,10 +829,10 @@ builddeps() {
 	if [ -n "$install_deps" ] && [ -z "$recursive" ]; then
 		# make a --simluate run first to detect missing deps
 		# apk-tools --virtual is no goot at reporting those.
-		$SUDO apk add --repository "$apkcache" \
+		$SUDO $APK add --repository "$apkcache" \
 			--wait 30 \
 			--simulate --quiet $deps || return 1
-		$SUDO apk add --repository "$apkcache" \
+		$SUDO $APK add --repository "$apkcache" \
 			--wait 30 \
 			--virtual .makedepends-$pkgname $deps \
 			&& return 0
@@ -841,7 +842,7 @@ builddeps() {
 
 	# find dependencies that are installed but missing in repo.
 	for i in $deps; do
-		local m=$(apk search --repository "$apkcache" ${i%[<>=]*})
+		local m=$($APK search --repository "$apkcache" ${i%[<>=]*})
 		if [ -z "$m" ]; then
 			missing="$missing $i"
 		fi
@@ -856,7 +857,7 @@ builddeps() {
 			cd "$dir" && $0 -k -r apkcache || return 1
 		fi
 	done
-	$SUDO apk add -u --repository "$apkcache" \
+	$SUDO $APK add -u --repository "$apkcache" \
 		--wait 30 \
 		--virtual .makedepends-$pkgname $deps
 }
@@ -963,24 +964,24 @@ post_add() {
 		die "$1 is not built by this APKBUILD"
 	fi
 	# recursively install dependencies that are provided by this APKBUILD
-	deps=$(apk index "$pkgf" 2>/dev/null | awk -F: '$1=="D" { print $2 }')
+	deps=$($APK index "$pkgf" 2>/dev/null | awk -F: '$1=="D" { print $2 }')
 	for i in $deps; do
 		if subpackages_has $i || [ "$i" = "$pkgname" ]; then
 			post_add $i || return 1
 		fi
 	done
-	$SUDO apk add --wait 30 -u "$pkgf" || die "Failed to install $1"
+	$SUDO $APK add --wait 30 -u "$pkgf" || die "Failed to install $1"
 }
 
 installdeps() {
 	local deps i
-	sudo apk add --wait 30 --repository "$apkcache" \
+	sudo $APK add --wait 30 --repository "$apkcache" \
 		--virtual .makedepends-$pkgname \
 		$makedepends
 }
 
 uninstalldeps (){
-	sudo apk del .makedepends-$pkgname
+	sudo $APK del .makedepends-$pkgname
 }
 
 all() {