Fix potentially misleading test failures

qa/rpc-tests/test_framework/util.py

@@ -358,8 +358,8 @@ def random_transaction(nodes, amount, min_fee, fee_increment, fee_variants):
 def assert_equal(expected, actual, message=""):
     if expected != actual:
         if message:
-            message = "%s; " % message 
-        raise AssertionError("%sexpected: <%s> but was: <%s>" % (message, str(expected), str(actual)))
+            message = "; %s" % message 
+        raise AssertionError("(left == right)%s\n  left: <%s>\n right: <%s>" % (message, str(expected), str(actual)))
 
 def assert_true(condition, message = ""):
     if not condition: