I'm not entirely sure if we're seeing the same issue described here, or something else but after moving to Xcode 14 there is some kind of bug that is adding a ~52s increase in an incremental build where I'm just making a relatively isolated one line change in a view controller.
In Xcode 13.4.1, the same incremental build takes ~23s and in Xcode 14.1 we're up to 75s which suggests that this one step is the issue. Furthermore, with the help of @Jon_Shier, I found that setting the SWIFT_USE_INTEGRATED_DRIVER build setting to NO brings the incremental build time in Xcode 14.1 back down to ~23s suggesting that the issue I'm facing relates to the new integrated driver that was added to Xcode:
- Swift driver, the component that orchestrates Swift front-end invocations, is now integrated into Xcode’s build system, allowing for more fine-grained dependencies to other build system tasks and explicit scheduling. (72440175)
Here's a screenshot where you can see the problematic step:
And the timing summary:
This is the raw invocation made by the 52s step:
SwiftDriver\ Compilation Global normal arm64 com.apple.xcode.tools.swift.compiler (in target 'Global' from project 'Global')
cd /Users/liamnichols/Code/GitHub/cookpad/global-ios/Global
builtin-Swift-Compilation -- /Applications/Xcode-14.1.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swiftc -module-name Global -Onone -enforce-exclusivity\=checked @/Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Intermediates.noindex/Global.build/Debug-iphonesimulator/Global.build/Objects-normal/arm64/Global.SwiftFileList -DXCODE_1400 -DDEBUG -Xfrontend -warn-long-function-bodies\=500 -Xfrontend -warn-long-expression-type-checking\=500 -D COCOAPODS -D COCOAPODS -sdk /Applications/Xcode-14.1.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator16.1.sdk -target arm64-apple-ios13.1-simulator -enable-bare-slash-regex -g -module-cache-path /Users/liamnichols/Library/Developer/Xcode/DerivedData/ModuleCache.noindex -Xfrontend -serialize-debugging-options -profile-coverage-mapping -profile-generate -enable-testing -index-store-path /Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Index.noindex/DataStore -swift-version 5 -I /Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator -F /Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator -F /Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/FirebaseABTesting -F /Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/FirebaseCore -F /Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/FirebaseCoreDiagnostics -F /Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/FirebaseCrashlytics -F /Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/FirebaseDynamicLinks -F /Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/FirebaseInAppMessaging -F /Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/FirebaseInstallations -F /Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/FirebaseMessaging -F /Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/FirebasePerformance -F /Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/FirebaseRemoteConfig -F /Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/GoogleDataTransport -F /Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/GoogleUtilities -F /Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/ListItemFormatter -F /Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/PromisesObjC -F /Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/nanopb -F /Users/liamnichols/Code/GitHub/cookpad/global-ios/Pods/FirebaseAnalytics/Frameworks -F /Users/liamnichols/Code/GitHub/cookpad/global-ios/Pods/FreshchatSDK -F /Users/liamnichols/Code/GitHub/cookpad/global-ios/Pods/GoogleAppMeasurement/Frameworks -F /Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/XCFrameworkIntermediates/FirebaseAnalytics/AdIdSupport -F /Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/XCFrameworkIntermediates/FreshchatSDK -F /Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/XCFrameworkIntermediates/GoogleAppMeasurement/AdIdSupport -F /Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/XCFrameworkIntermediates/GoogleAppMeasurement/WithoutAdIdSupport -c -j10 -enable-batch-mode -incremental -output-file-map /Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Intermediates.noindex/Global.build/Debug-iphonesimulator/Global.build/Objects-normal/arm64/Global-OutputFileMap.json -use-frontend-parseable-output -save-temps -no-color-diagnostics -serialize-diagnostics -emit-dependencies -emit-module -emit-module-path /Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Intermediates.noindex/Global.build/Debug-iphonesimulator/Global.build/Objects-normal/arm64/Global.swiftmodule -Xcc -I/Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Intermediates.noindex/Global.build/Debug-iphonesimulator/Global.build/swift-overrides.hmap -Xcc -iquote -Xcc /Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Intermediates.noindex/Global.build/Debug-iphonesimulator/Global.build/Global-generated-files.hmap -Xcc -I/Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Intermediates.noindex/Global.build/Debug-iphonesimulator/Global.build/Global-own-target-headers.hmap -Xcc -I/Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Intermediates.noindex/Global.build/Debug-iphonesimulator/Global.build/Global-all-non-framework-target-headers.hmap -Xcc -ivfsoverlay -Xcc /Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Intermediates.noindex/Global.build/Debug-iphonesimulator/Global.build/all-product-headers.yaml -Xcc -iquote -Xcc /Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Intermediates.noindex/Global.build/Debug-iphonesimulator/Global.build/Global-project-headers.hmap -Xcc -I/Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/include -Xcc -I/Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/FirebaseABTesting/FirebaseABTesting.framework/Headers -Xcc -I/Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/FirebaseCore/FirebaseCore.framework/Headers -Xcc -I/Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/FirebaseCoreDiagnostics/FirebaseCoreDiagnostics.framework/Headers -Xcc -I/Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/FirebaseCrashlytics/FirebaseCrashlytics.framework/Headers -Xcc -I/Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/FirebaseDynamicLinks/FirebaseDynamicLinks.framework/Headers -Xcc -I/Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/FirebaseInAppMessaging/FirebaseInAppMessaging.framework/Headers -Xcc -I/Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/FirebaseInstallations/FirebaseInstallations.framework/Headers -Xcc -I/Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/FirebaseMessaging/FirebaseMessaging.framework/Headers -Xcc -I/Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/FirebasePerformance/FirebasePerformance.framework/Headers -Xcc -I/Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/FirebaseRemoteConfig/FirebaseRemoteConfig.framework/Headers -Xcc -I/Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/GoogleDataTransport/GoogleDataTransport.framework/Headers -Xcc -I/Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/GoogleUtilities/GoogleUtilities.framework/Headers -Xcc -I/Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/ListItemFormatter/ListItemFormatter.framework/Headers -Xcc -I/Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/PromisesObjC/FBLPromises.framework/Headers -Xcc -I/Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Products/Debug-iphonesimulator/nanopb/nanopb.framework/Headers -Xcc -I/Users/liamnichols/Code/GitHub/cookpad/global-ios/Pods/Headers/Public -Xcc -I/Users/liamnichols/Code/GitHub/cookpad/global-ios/Pods/Headers/Public/Firebase -Xcc -I/Users/liamnichols/Code/GitHub/cookpad/global-ios/Pods/Firebase/CoreOnly/Sources -Xcc -I/Sources/FBLPromises/include -Xcc -I/Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Intermediates.noindex/Global.build/Debug-iphonesimulator/Global.build/DerivedSources-normal/arm64 -Xcc -I/Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Intermediates.noindex/Global.build/Debug-iphonesimulator/Global.build/DerivedSources/arm64 -Xcc -I/Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Intermediates.noindex/Global.build/Debug-iphonesimulator/Global.build/DerivedSources -Xcc -DDEBUG\=1 -Xcc -DCOCOAPODS\=1 -Xcc -DDEBUG\=1 -Xcc -DPB_FIELD_32BIT\=1 -Xcc -DPB_NO_PACKED_STRUCTS\=1 -Xcc -DPB_ENABLE_MALLOC\=1 -emit-objc-header -emit-objc-header-path /Users/liamnichols/Library/Developer/Xcode/DerivedData/Global-gxqyyvwrahgvtoabmdmcefksioce/Build/Intermediates.noindex/Global.build/Debug-iphonesimulator/Global.build/Objects-normal/arm64/Global-Swift.h -working-directory /Users/liamnichols/Code/GitHub/cookpad/global-ios/Global -experimental-emit-module-separately
In my best attempt to try and recompile only the Global (this is the main iOS app) target and not the dependencies, I deleted Build/Intermediates.noindex/Global.build, Products/Debug-iphonesimulator/Global.app and Products/Debug-iphonesimulator/Global.swiftmodule and re-built the project. This took a total of 68.4s. (less than the 75s incremental build) where the exact same problematic 52s invocation from above took only 0.1s
And the timing summary looks significantly different too:
I guess that one of my questions here is "what is the difference between 'SwiftCompile' and 'SwiftDriver Compilation'? I have no idea if the above is helpful, but I hope it might be.
@Slava_Pestov, @codafi: I attached logs and screenshots to FB11768802 and while I can't share the project source, neither do I know how to create a reproducer, I would be happy to jump on a video call to show you the issue if it helps.