I using ant exec task to execute xcodebuild to build some iOS projects hudson. I would like to be able to crate script that way that allows not to specify sdk version, because after updating sdk on hudson slave or my iOS projects all my projects failing....

There is is nice option in xcode since sdk 4.2 in target setup Base SDK - Latest iOS

and I don't have to provide -sdk param in xcodebuild command, but then (i think) it's taken from xcode project and it's bad because then some one can change target from simulator to device accidentally during commit.

I need something that is constant. I will prefer not to use env variable because I would like to be able to run this ant task also on dev machines and would like not have to renember about setting it on all machines.

Unfortunately xcodebuild -showsdk gives only:

Mac OS X SDKs:
    Mac OS X 10.4                   -sdk macosx10.4
    Mac OS X 10.5                   -sdk macosx10.5
    Mac OS X 10.6                   -sdk macosx10.6

iOS SDKs:
    iOS 4.2                         -sdk iphoneos4.2

iOS Simulator SDKs:
    Simulator - iOS 3.2             -sdk iphonesimulator3.2
    Simulator - iOS 4.0             -sdk iphonesimulator4.0
    Simulator - iOS 4.1             -sdk iphonesimulator4.1
    Simulator - iOS 4.2             -sdk iphonesimulator4.2

I need something like -sdk iphoneosLatest. My only idea is to pare output of xcodebuild -showsdk with some script, but I don't like this idea.