My friend just updated my Mac to Mac OS X Lion GM (Since it would take me a LONG time to download Lion when it comes out, though I'm still purchasing Lion). It turns out that Any Xcode version BEFORE 4.2 is NOT supported on Lion. This means that no Xcode which has iOS SDK 4 is supported on Mac OS X Lion. I installed Xcode 4.2 (which comes with iOS SDK 5 beta). After opening a Buzztouch project, I'm getting hundreds of errors! It seems as it's no easy fix, either. Just a warning to BuzzTouch users out there: DO NOT UPDATE TO LION. Doing so will make it so you cannot compile any BuzzTouch projects. Hopefully Dave will have a fix for this soon. Lion has some pretty new awesome feature, but I'm not sure if it is worth updating since I cannot make any more apps using BuzzTouch. The worst part: I lost my Snow Leopard installation (restore) disc, and therefore I'm probably not going to be able to use BuzzTouch until a fix is released. Thank you

Sounds like a bummer. Everytime Mac updates the iOS or they update Xcode there are issues with the compiling process. Sometimes they seem drastic and it looks like there are tons of them but we generally don't have too much trouble finding and fixing them. We've done this through a few updates. Mac OSX Lion or other OS upgrades don't usually cause the trouble. THe trouble is usually iOS upgrades on the devices and the SDK. Maybe this time it's a whole new issue - who knows. You are the second person to report this, it will get more important (to us, sorry) when iOS 5 is officially release. In the meantime, are you sure you can't get your previous verison of the iOS SDK to run? Oh, lastly, the previous report had nothing to do with Lion and EVERYTHING to do with iOS 5. It's probably the new SDK and not your computers OS.

Hello David, Xcode versions before 4.2 are not supported on Lion. I even re-downloaded Xcode on the Mac App Store and it failed to install because I am running Lion. Sucks...

Okay, Apple released Xcode 4.1 today. Guess I got to re-download Xcode, again. Hope it works!

Already installed Lion on my iMac but not on my macbook. phew.

Hopefully Xcode 4.1 will be supported and we will have no problems. Fingers crossed :)

My projects and simulator works fine for me after LION+Xcode4.1 upgrade, haven't tried on my iphone yet thought. I will write the result after I test. And a tip while installing LION: The installation countdown went to '6 minutes left', then gone back to '18 minutes left' and seemed to freeze. I've waited sometime and it continued to install. So don't power off your mac if this happens, just be calm. Oh and if your screen goes black and you can't get a picture by moving the mouse/trackpad, just double-click. Hope this helps :)

no issues here either with xcode 4 and lion.