--- a/build	Tue Apr 07 21:08:49 2015 +0200
+++ b/build	Wed Apr 08 21:58:06 2015 +0200
@@ -1,7 +1,9 @@
 #!/bin/bash
+make -C platforms
 set -e
 test -d exim || {
     echo "exim src directory missing" >&2
+    echo "try: git clone https://github.com/Exim/exim.git" >&2
     exit 1
 }
 for dockerfile in ${*:-platforms/*/Dockerfile}