From 2d19a9446e44197ff3d726c4384522938262ee2c Mon Sep 17 00:00:00 2001
From: Iain Lane <iain.lane@canonical.com>
Date: Tue, 3 Sep 2019 14:52:30 +0100
Subject: [PATCH] snap_preseed: Handle SNAP_NO_VALIDATE_SEED being unset

Some builds run with `set -u` and were broken due to this.
---
 live-build/functions | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/live-build/functions b/live-build/functions
index 9bbab33a..c5a63444 100644
--- a/live-build/functions
+++ b/live-build/functions
@@ -656,7 +656,7 @@ snap_preseed() {
     # i.e. snaps with bases need to add bases first etc
     #
     # Skip validation by setting SNAP_NO_VALIDATE_SEED=1.
-    if [ -z "${SNAP_NO_VALIDATE_SEED}" ]; then
+    if [ -z "${SNAP_NO_VALIDATE_SEED:-}" ]; then
         snap_validate_seed "${CHROOT_ROOT}"
     fi
 }