private static String determineSystemRoot() throws IOException {
		String whileyhome = System.getenv("WHILEYHOME");
		if (whileyhome == null) {
			System.err.println("error: WHILEYHOME environment variable not set");
			System.exit(-1);
		}
		return whileyhome;
	}
private static String determineSystemRoot() throws IOException {
		String whileyhome = System.getenv("WHILEYHOME");
		if (whileyhome == null) {
			System.err.println("error: WHILEYHOME environment variable not set");
			System.exit(-1);
		}
		return whileyhome;
	}
private static String determineSystemRoot ( ) throws IOException { String whileyhome = System . getenv ( "WHILEYHOME" ) ; if ( whileyhome == null ) { System . err . println ( "error: WHILEYHOME environment variable not set" ) ; System . exit ( - 1 ) ; } return whileyhome ; }
Determine the system root. That is, the installation directory for the
compiler itself.

@param tool
@return
@throws IOException
Determine the system root . That is the installation directory for the compiler itself .