The default recognition error messages in antlr C++ backend are different from Java backend which makes Scylla's CQL error messages incompatible with Cassandra. This makes it very hard to write CQL level test cases which are portable between Scylla and Cassandra. To fix the issue, override the most common lexer and parser error messages to follow the convention set by the antlr Java backend. This unlocks various test cases in AlterTest, for example. Message-Id: <1460032883-14422-1-git-send-email-penberg@scylladb.com>