I upgraded to Xcode 3.2.3 with the latest version of the iPhone SDK version 4, and I know that for publishing on the App Store your application must be ready for iOS (SDK 4).
But many of my beta testers (including me) still work with OS 3.1.x (latest version) and may not upgrade to iOS4 because it slows down their phone to bypass (mainly for those who have 3G, not 3GS). I initially upgraded to 4.0, but it was so painful that I had to go back to 3.1.x so that I could use my phone.
Can I build application builds to run on an older OS with SDK 4? When I tried it myself, iTunes told me that my phone operating system is an older version and it does not start it.
In Xcode, I have only two possible values for the Base SDK - iPhone Device 3.2 and iPhone Device 4.0. When I tried to change the base SDK to “iPhone Device 3.2”, I received a build warning:
warning: creation using the "Target" Device Family "is installed only on the iPhone ('1') is not supported using the SDK 'Device - iPhone OS 3.2'.
On my machine in /Developer/Platforms/iPhoneOS.platform I have two SDKs listed (which correspond to the Base SDK options shown in Xcode):
Developer/SDKS/iPhoneOS3.2.sdk
Developer/SDKS/iPhoneOS4.0.sdk
In the DeviceSupport / folder, I have the following versions:
3.0
3.1
3.1.2
3.1.3
3.2
4.0
Is it possible to create assemblies for my users with versions without iOS4, or do I need to make them (as well as me) live with slowness on phones?