How to set Swift version 5 (for recent dev snapshots) in Xcode build settings?

[tkremenek (Ted Kremenek)]

@Aciid

Ok, it looks the build system always validates the value of SWIFT_VERSION against the hardcoded list so there is no way make it work with the latest version of Xcode. I'll go ahead and file some radars. We definitely need some solution here :/

Here is a hack that works for trying out the snapshots in Swift 5 mode:

1. Edit the file /Applications/Xcode.app/Contents/PlugIns/Xcode3Core.ideplugin/Contents/SharedSupport/Developer/Library/Xcode/Plug-ins/XCLanguageSupport.xcplugin/Contents/Resources/Swift.xcspec

2. Search for SupportedLanguageVersions and add 5.0 as a valid value.