| Signal Int -- some other fatal signal (SIGHUP,SIGTERM)
| UsageError String -- prints the short usage msg after the error
| CmdLineError String -- cmdline prob, but doesn't print usage
| Signal Int -- some other fatal signal (SIGHUP,SIGTERM)
| UsageError String -- prints the short usage msg after the error
| CmdLineError String -- cmdline prob, but doesn't print usage