Base SDK missing after a fresh install of XCode 3.2.5 which includes iOS SDK 4.2

Question

I'm new to iPhone development. I just did a fresh install of XCode 3.2.5 with iOS SDK 4.2. No previous XCode or iOS versions have been installed before. However trying to compile some sample project from some books gives "Base SDK Missing". :( What to do? How can I use XCode 3.2.5 for older iPhones like 3GS if it only supports 4.2?

When I go to "Project/Edit Project Settings/Architecture/Base SDK/iOS SDK's" only iOS 4.2 is available to be selected.

Do I need to install older XCode first and then upgrade?

Answer 1

In the build settings, you can support older phones by setting "iOS Deployment Target" to something like 3.0. http://developer.apple.com/library/mac/#documentation/DeveloperTools/Conceptual/cross_development/Configuring/configuring.html has more details on the difference between this and the Base SDK setting.

Answer 2

Set Project/Edit Project Settings/Architecture/Base SDK to the Latest OS version, then quit and restart Xcode. You can later set the Deployment target to a lower OS version.

Answer 3

I had the same problem for most of the afternoon. I did everything suggested and nothing worked UNTIL I cleaned and cleaned and saved and rebooted and re-built. Unfortunately that doesn't tell me what actually worked, but it does give everyone "just one more thing" to try.