If anyone is having issues compiling pjsip with the new XCode 4.2 + iOS 5 GM, I had to change the host in configure-iphone script on the following line: ./aconfigure --host=arm-apple-darwin9 --disable-floating-point $* to ./aconfigure --host=arm-apple-darwin10 --disable-floating-point $* in order to make the pjsip library compile. Best regards, Even Andr?