Trap: ugly error message

[h0nzZik]

Executing the program

int main() {
    int x;
    int y = x;
}

results in the error message:

Fatal error: exception Invalid_argument("mismatched constructor at top of split configuration: inRangeCpp(trap(.KList), tcpp(quals(`.Set`(.KList)), `.Set`(.KList), `int_CPP-TYPING-SYNTAX`(.KList)))")
[Error] Critical: Failed to execute program in ocaml. See output for error
information.

If the program is well-defined, there should be no error message. If it is undefined, it should say so.