-rm_and_mkdir ./tri-out
-apitrace dump-images -o ./tri-out/tri tri.trace
-EXPECT_FAILURE: apitrace diff-images -v ./tri-ref-mismatch ./tri-out
-expect "Comparing ./tri-ref-mismatch/tri0000000027.png and ./tri-out/tri0000000027.png ... MISMATCH\n"
+EXPECT_FAILURE: apitrace diff-images --verbose images/white-1x1/ images/black-1x1/
+
+# In addition to getting the return value indicating an error, let's
+# also require that "apitrace diff-images" gave us the output we
+# expect.
+
+expect "Comparing images/white-1x1/0.png and images/black-1x1/0.png ... MISMATCH\n"