Failing to install RxSwift 6.0 using Carthage on Xcode 12

[alcamla]

Short description of the issue:

After creating a new project, added github "ReactiveX/RxSwift" "6.0.0-rc.1" as dependency. Then, running carthage update --platform iOS fails

Expected outcome:

Carthage succeeds to install RxSwift

What actually happens:

Building scheme "RxBlocking" in Rx.xcworkspace Build Failed Task failed with exit code 1: /usr/bin/xcrun lipo -create /Users/myUser/Library/Caches/org.carthage.CarthageKit/DerivedData/12.0_12A7209/RxSwift/6.0.0-rc.1/Build/Intermediates.noindex/ArchiveIntermediates/RxBlocking/IntermediateBuildFilesPath/UninstalledProducts/iphoneos/RxBlocking.framework/RxBlocking /Users/myUser/Library/Caches/org.carthage.CarthageKit/DerivedData/12.0_12A7209/RxSwift/6.0.0-rc.1/Build/Products/Release-iphonesimulator/RxBlocking.framework/RxBlocking -output /Users/alejandrocamacho/Desktop/TestRx/Carthage/Build/iOS/RxBlocking.framework/RxBlocking

Self contained code example that reproduces the issue: Create project Create cartfile with github "ReactiveX/RxSwift" "6.0.0-rc.1" as dependency Run carthage update --platform iOS

Platform/Environment

• [X] iOS
• [ ] macOS
• [ ] tvOS
• [ ] watchOS
• [ ] playgrounds

How easy is to reproduce? (chances of successful reproduce after running the self contained code)

• [X] easy, 100% repro
• [ ] sometimes, 10%-100%
• [ ] hard, 2% - 10%
• [ ] extremely hard, %0 - 2%

Xcode version:

  Xcode 12.1

Installation method:

• [ ] CocoaPods
• [X] Carthage (0.34.0)
• [ ] Git submodules

I have multiple versions of Xcode installed: (so we can know if this is a potential cause of your issue)

• [ ] yes (which ones)
• [X] no

[alcamla]

With a bit more digging into this issue found out that this is a general problem with Carthage #319 and using this script is a temporal workaround.