From 6c736fa47202bcffb4f056d6e5b2f12424e9f758 Mon Sep 17 00:00:00 2001
From: Dan Callahan <danc@element.io>
Date: Thu, 21 Oct 2021 22:58:48 +0100
Subject: [PATCH] Fix Shellcheck SC2154: variable possibly undefined

var is referenced but not assigned.

https://github.com/koalaman/shellcheck/wiki/SC2154

Signed-off-by: Dan Callahan <danc@element.io>
---
 docker/build_debian.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/docker/build_debian.sh b/docker/build_debian.sh
index 801ff45471..1d0be42cfc 100644
--- a/docker/build_debian.sh
+++ b/docker/build_debian.sh
@@ -5,7 +5,7 @@
 set -ex
 
 # Get the codename from distro env
-DIST=`cut -d ':' -f2 <<< $distro`
+DIST=`cut -d ':' -f2 <<< ${distro:?}`
 
 # we get a read-only copy of the source: make a writeable copy
 cp -aT /synapse/source /synapse/build