Xcode

There is always a penalty for using bleeding edge stuff. In the case of Swift, there has been significant penalties for early adopters as people have already discovered.From my understanding, people who have deployed Swift 1.x apps before will be forced to update to Swift 2 if they want to target anything specific to iOS 9 or OS X 10.11 (assuming those SDKs will not be available for Swift 1.x on Xcode 6 at least officially). Otherwise, it is safer to stay with Swift 1.x on Xcode 6 for now (and even more safer if you had not adopted Swift at all so you can target latest APIs in Xcode 7 without penalties).They have not officially confirmed yet which older iOS or OS X versions will be (and not be) supported for Swift 2. So, I am not sure how one can make a safe and informed decision on a migration path for a significant project using Swift.What is your compelling use case that requires you to convert an existing project to Swift 2? Worth thinking about.If the new language constructs, l

You might be right that it is part of the reason. But they didn't have to make it open source for that reason alone. Nothing prevented them from keeping their Linux port to themselves.You make it open source if there is a benefit in either driving adoption or in faster and more efficient testing and bug fixes. Swift probably reached a plateau in adoption and was surely straining their resources in testing and bug fixing given its evolution history. Now they can deploy more of those testing and maintanence resources into Xcode (which is falling behind in capabilities relative to the latest IDEs in my opinion) as well as Apple SDK support.

You can't use that feature if you're running iOS 8.4, because there is no Developer Disk Image available for it in Xcode 7 as i figured. This is your problem if you're running 8.4 and get an error message similar to this one: Could not find Developer Disk Image

I just found out that iOS 8.4 wasn't supported by Xcode 7 and there's no Developer Disk Image available for it. I guess we'll have to wait until iOS 9 public beta then or try downgrading to 8.3.

ddeacon22 posted something that could help you here: https://forums.developer.apple.com/thread/3785Also, if you run iOS 8.4 on your device, that is not supported by Xcode 7 until now.

Right - people have noted that. But in the past Apple usually put the same release in the Downloads folder. Its not there. I don't want to pull it from the App Store due to reported complications by others (which may or may not exist, but the fact remains many devs are leary of using the App Store for Xcode).

Same here. Every time I try to view a storyboard or .xib in Xcode 7, I get this exception:UNCAUGHT EXCEPTION (NSInvalidArgumentException): *** -containsValueForKey: only defined for abstract class. Define -[NSUnarchiver containsValueForKey:]!I can run the app fine, I just can't actually view or edit my storyboard/.xibs in Xcode anymore!Stack trace:Process: Xcode [4209] Path: /Applications/Xcode-beta.app/Contents/MacOS/Xcode Identifier: com.apple.dt.Xcode Version: 7.0 (8123.26) Build Info: IDEFrameworks-8123026000000000~7 Code Type: X86-64 (Native) Parent Process: ??? [1] Responsible: Xcode [4209] User ID: 501 Date/Time: 2015-06-10 15:05:14.928 -0400 OS Version: Mac OS X 10.10.3 (14D136) Report Version: 11 Anonymous UUID: 9B7324FE-113A-BF78-0590-ECC7DDE67CD9 Sleep/Wake UUID: A68D9DCC-EE2D-439B-B979-F232409B3139 Time Awake Since Boot: 10000 seconds Time Since Wake: 3700 seconds Crashed Thread: 0 Dispatch queue: com.apple.main-thread Excepti