diff --git a/src/test-all.sh b/src/test-all.sh
index f6dca84322..c0d9977ed1 100755
--- a/src/test-all.sh
+++ b/src/test-all.sh
@@ -1,5 +1,11 @@
 #!/bin/bash
+
+# Exit immediately on errors.
+set -e
+
+# Run from the src/tools directory which includes all our crates.
 cd $(dirname "$0")/tools
+
 PKGS="-p cretonne -p cretonne-reader -p cretonne-tools"
 cargo build $PKGS
 cargo doc  $PKGS