code compiles just fine but the resulting binary doesn't handle exceptions as expected.
little testcase which prints out "uncought":

using GLib;
public class Test : Object {
	public static int main(string[] args) {
		string s;
		try {
			s = foo(); // <-- works when removing "s = "
			if (s == null)
				stdout.printf("uncought\n");
		}
		catch(DummyError err) {
			stdout.printf("cought\n");
		}
		return 0;
	}

	public static string foo() throws DummyError {
		throw new DummyError.CATCHME("foo");
	}
}

public errordomain DummyError { CATCHME }