ios - Xcode 9 Swift Language Version (SWIFT_VERSION)

Question

I've recently updated xcode to version 9. Before that in Xcode 8.x whenever I use to do pod update it shows me an update code to convert the code to Swift 3 and doing that solve the errors. But now it is giving me this error:

The “Swift Language Version” (SWIFT_VERSION) build setting must be set to a supported value for targets which use Swift. This setting can be set in the build settings editor.

For this error I've tried Build Settings > Swift Language Version and it was Swift 3.2 But as the update call has re-installed some of the pods like Alamofire and it says to install Xcode 8.x to convert the code to Swift 3 so do I need to install an additional version with the latest Xcode? If yes, then how can I install Xcode 8 with Xcode 9?

Answer 1

Answer to your question:
You can download Xcode 8.x from Apple Download Portal or Download Xcode 8.3.3 (or see: Where to download older version of Xcode), if you've premium developer account (apple id). You can install & work with both Xcode 9 and Xcode 8.x in single (mac) system. (Make sure you've Command Line Tools supporting both version of Xcode, to work with terminal (see: How to install 'Command Line Tool'))

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Hint: How to migrate your code Xcode 9 compatible Swift versions (Swift 3.2 or 4)
Xcode 9 allows conversion/migration from Swift 3.0 to Swift 3.2/4.0 only. So if current version of Swift language of your project is below 3.0 then you must migrate your code in Swift 3 compatible version Using Xcode 8.x.

This is common error message that Xcode 9 shows if it identifies Swift language below 3.0, during migration.

Swift 3.2 is supported by Xcode 9 & Xcode 8 both.

Project ? (Select Your Project Target) ? Build Settings ? (Type 'swift' in Searchbar) Swift Compiler Language ? Swift Language Version ? Click on Language list to open it.

Convert your source code from Swift 2.0 to 3.2 using Xcode 8 and then continue with Xcode 9 (Swift 3.2 or 4).

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For easier migration of your code, follow these steps: (it will help you to convert into latest version of swift supported by your Xcode Tool)

Xcode: Menus: Edit ? Covert ? To Current Swift Syntax