diff --git a/testing/errors/opnotsupp-FIXME.a b/testing/errors/opnotsupp-FIXME.a
new file mode 100644
index 0000000..ee52752
--- /dev/null
+++ b/testing/errors/opnotsupp-FIXME.a
@@ -0,0 +1,3 @@
+;ACME 0.96.5
+	li = [[9,8], 7, 3,4]
+	a = len(li)[0]	; this should give an "Operation not supported" error, but doesn't