Swift does not support the SDK 'iPhoneSimulator9.3.sdk'?

Question

I have just installed the xcode 8.0 and upgrade my project to swift 3. I was using swift 2.2 and xcode 7.3.1.

But getting following error:

Swift does not support the SDK 'iPhoneSimulator9.3.sdk'

Command /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swiftc failed with exit code 1

Answer 1

This happened to me when I had simultaneously installed both Xcode 7 and 7.3 and after automatic update I was left with 8.0 only.

One indication that something got messed up was output of xcodebuild -sdk -version in terminal:

DVTSDK: Warning: SDK path collision for path '<DVTFilePath:0x7fd810db4c50:'/Applications/Xcode.app/Contents/Developer/Platforms/WatchOS.platform/Developer/SDKs/WatchOS3.0.sdk'>': SDK with name 'watchos3.0' being superceded by SDK with 'watchos3.0'.

Solution:

1. Quit Xcode
2. go to /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/
3. remove the iPhoneOS9.3.sdk folder from that directory. Be sure to make an external copy if you still need it so you can put it back later.
4. restart Xcode, clean, and build
5. ???
6. PROFIT

UPDATE:

According to @tsafrir comment, delete also 'iPhoneOS9.3.sdk' for simulator folder: /Applications/Xcode.app/Contents/Developer/Platforms/iPhon‌​eSimulator.platform/‌​Developer/SDKs