pragma experimental SMTChecker; contract C { function f() public payable { assert(msg.data.length > 0); } } // ---- // Warning: (86-101): Assertion checker does not yet support this expression. // Warning: (86-94): Assertion checker does not yet support this global variable. // Warning: (86-101): Internal error: Expression undefined for SMT solver. // Warning: (79-106): Assertion violation happens here