warning: Insecure world writable dir /usr/local/bin in PATH, mode 040777
解决方法：
sudo chmod 775 /usr/local
tips：
775 => root(7) group(7) others(5), 7 => read(4) + write(2) + execute(1), and 5 => read(4) + execute(1)
原文：http://www.cnblogs.com/superchao8/p/3976705.html