Xcode 10.2, Swift 5, Command compileSwift failed while build the program with Release Scheme

I'm using Xcode 10.2, Swift 5.

With Debug scheme, no issue happens, but with Release scheme when I build or archive, it shows Command compileSwift failed with a nonzero exit code.

I've tried delete DerivedData / Clean / pod deintegrate & pod install & pod update. None of these works.

For my project problem was related to pod Cache which gives error when Optimization Level for Release is set to Optimize for Speed [-O]. I have set Compilation Mode to Whole Module again and set optimization level for the pod in pod file:

post_install do |installer|
  installer.pods_project.targets.each do |target|
    # Cache pod does not accept optimization level '-O', causing Bus 10 error. Use '-Osize' or '-Onone'
    if target.name == 'Cache'
      target.build_configurations.each do |config|
        level = '-Osize'
        config.build_settings['SWIFT_OPTIMIZATION_LEVEL'] = level
        puts "Set #{target.name} #{config.name} to Optimization Level #{level}"
      end
    end
  end
end

Refrence: https://github.com/hyperoslo/Cache/issues/233#issuecomment-477749560

I fixed this issue by going Pods Project then to the building settings and setting Compilation Mode to Incremental for Release. Then clean and archive, should compile fine then.

So I had same issue when updating my project to Swift 5. For some reason, Cocoapods (latest version, 1.6.1) set the SWIFT_VERSION of some pods to Swift 5 even if they're released as Swift 4, 4.1, 4.2 pods. So I had to add a post install script that set the correction version of swift like so

post_install do |installer|
  installer.pods_project.targets.each do |target|
    if target.name == 'CryptoSwift' || target.name == 'SwiftyBeaver'
      target.build_configurations.each do |config|
        config.build_settings['SWIFT_VERSION'] = '4.2'
      end
    end
  end
end

I had the same issue after upgrading to Xcode 10.2. After following the steps below it worked for me:

Update pods
Clean project folder
Change Pods project's Swift Language Version to Unspecified and (as suggested by @Neil Faulkner) Compilation Mode to Incremental

I had to set "Optimization Level" in "Swift Compiler - Code Generation" to "Release" - "No Optimization [-Onone]" from "Optimize for speed" to make Cache pass Archive.

Same with SwiftyBeaver

It seems a problem related to Xcode 10.2. Also other pod projects seems to be fine with Optimization, like Toucan or XCGLogger.

you can follow this steps...