warning: Insecure world writable dir .../osx/bin in PATH, mode 040777 with Homebrew

I'm using homebrew for compiling/installing Mac command line tools. It uses ruby for implementation, and whenever I user homebrew install SOMETHING, I got warning: Insecure world writable dir .../osx/bin in PATH, mode 开发者_StackOverflow社区040777 warnings. The bin directory has permission of 777. Why is this warnings, and how do I remove them?

It's generally not a good idea to have a 777 directory in your path because other users can put executables in there and trick you into running them with your privileges. To fix, just change it to 755 or 775. (Of course, if you're the only user of your computer, you have nothing to worry about.)