diff --git a/build.debug.sh b/build.debug.sh
new file mode 100755
index 0000000..9427117
--- /dev/null
+++ b/build.debug.sh
@@ -0,0 +1,19 @@
+#!/bin/sh -eu
+
+w1="$(mktemp out_$$_1_XXXX.js)"
+
+#elm make --optimize --output=${w1} src/Main.elm 1>&2
+elm make --output=${w1} src/Main.elm 1>&2
+sed -i -e 's!console.warn(!console.log(!g' ${w1}
+
+w2="$(mktemp out_$$_XXXX.js)"
+
+cat dom.js ${w1} launch.js > ${w2}
+
+rm ${w1}
+
+qjs --std ${w2}
+
+# if qjs fails, output file will stay for debugging, else
+
+rm ${w2}