Xcode 10.2 Module compiled with Swift 4.2 cannot be imported by the Swift 5.0 compiler [duplicate]

Question

I am trying to implement integration of third party app into project as per instruciton https://github.com/Paytm-Payments/Paytm_iOS_App_Kit/tree/master/Swift/BitCodeDisabled/PaytmNativeSDK

I see the following error in build

Module compiled with Swift 4.2.1 cannot be imported by the Swift 5.0 compiler

I have tried toolchains https://medium.com/xcblog/switching-swift-versions-inside-xcode-using-toolchains-755b28831c43 The error changes to Reason: Incompatible library version: PaytmNativeSDK requires version 1.0.0 or later, but libswiftCore.dylib provides version 0.0.0

How do i setup XCode or the Library to make it work . There is no chance of the vendor updating the library for Swift 5.0 and make it available on POD.

Answer 1

For Carthage users: After upgrading to Xcode 10.2, I ran into this same issue with a framework that I had been importing using Carthage.

I resolved it by rebuilding the framework:

carthage update --no-use-binaries --platform iOS

Answer 2

The correct solution is download Xcode 10.1, and wait for Apple patch the bug fix.

Don't waste time on fix third-party bug.

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The problem of my project is we are using Alamofire which is failed to update by Carthage.

Answer 3

The provider of this library should rebuild it with BUILD_LIBRARY_FOR_DISTRIBUTION = YES; (available in Xcode 11.3 in Build Settings -> Build Options). Already asked to do it in the corresponding GitHub issue. After that PaytmNativeSDK will be compatible with every next Swift version.

It looks like the issue has been fixed in 804152caae76245d96548eb74ea87a6150239407.