From: Ubuntu Developers <ubuntu-devel-discuss@lists.ubuntu.com>
Date: Tue, 18 Jul 2017 17:21:09 +0800
Subject: ubuntu-allow-downgrades

---
 scripts/build/lb_chroot_archives | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/scripts/build/lb_chroot_archives b/scripts/build/lb_chroot_archives
index 379b591..5976cd8 100755
--- a/scripts/build/lb_chroot_archives
+++ b/scripts/build/lb_chroot_archives
@@ -564,8 +564,8 @@ EOF
 			rm -rf chroot/var/cache/apt/*.bin
 
 			Apt chroot update
-			Apt chroot "upgrade"
-			Apt chroot "dist-upgrade"
+			Apt chroot "--force-yes" "upgrade"
+			Apt chroot "--force-yes" "dist-upgrade"
 
 			if [ "${LB_CACHE_INDICES}" = "true" ]
 			then
