To disable System Integrity Protection, boot into recovery mode by restarting and then holding ⌘R as you hear the startup chime. Then start the Terminal from the Utilities menu. Run the following command $ csrutil disable Then reboot. You are good to go. If you wish to turn it back on, which you probably should when you are done, follow the instructions above but instead use: $ csrutil enable The first step is to install the latest and greatest Xcode. Install the Xcode developer tools. Apple seems to have removed this option from the preferences so you'll need to handle this from the command line. $ xcode-select --install Next we will install the required dependencies. If you are not already using Homebrew you should be. $ brew install wget autoconf pkg-config libmemcached You will also want to make sure you have PEAR installed; instructions can be found here but can be summarized as follows: $ wget http://pear.php.net/go-pear.ph...