The following code will make valac crash if one forgets to include config.vapi and this is causing anjuta to crash (bug 651151)

public class Main : Object 
{
        const string UI_FILE = Config.PACKAGE_DATA_DIR;
        static int main (string[] args) 
        {
                return 0;
        }
}

Here is the backtrace:

Program received signal SIGSEGV, Segmentation fault.
0xb7d0072b in vala_data_type_compatible (self=0x0, target_type=0x9d661a0)
    at /home/dev/GNOME/vala/vala/valadatatype.vala:311
311		public virtual bool compatible (DataType target_type) {
(gdb) bt

+ Trace 227983