Mac – Why does the App Store think Xcode 4.2 is installed

Don't accept this answer without vetting it further first, but I think I noticed something during my install.

I think that you don't get any SDKs as part of the XCode 4 install. It was only after I installed XCode 4 and launched it, that the project window showed a download in progress. Clicking it gave me the option of downloading: OSX 10.6 SDK, Legacy OSX SDK, iOS SDK, and something else that I don't remember at the moment. Perhaps extended documentation.

So, the XCode install itself is still very heavy. What with XCode visually, all it's associated applications and libraries, Clang/LLVM/LLDB, profiling tools, and everything.

But, the SDKs themself? I don't think it comes automatically. I can't seem to figure out how to get back to choose the other SDKs to download, so I'm not 100% sure in this.

Check your applications folder for the Xcode 4.1 application installer. This is what the Mac App Store actually downloads and is probably reported as installed. Run that again to reinstall.