How to install iPhone SDK 3.1.2 with xCode 3.1.4 on Mac OS X 10.5.5

After a clean install, I need to install the xCode with iPhone SDK again on Mac OS X 10.5.5. However, you should see an error telling you that it support 10.5.7 and above. To resolve this, you can do the following.

1. Edit the file /System/Library/CoreServices/SystemVersion.plist under superuser mode. I like to use vim

sudo vim /System/Library/CoreServices/SystemVersion.plist

The password should be your user password.

2. Change all the 10.5.5 to 10.5.7

3. Save and exit.

4. Start installing!