The error message for const Symbol of private identifiers should be better.

[floitschG]

Creating private symbols using the const Symbol constructor breaks DDC:

main() {
  print(const Symbol("_foo"));
}

yields the following error:

[error] Evaluation of this constant expression throws an exception.

[floitschG]

It seems like this is expected behavior.
Keeping the bug open for a better error message: it should state that private symbols can't be built, unless there is a library-mirror.