Xcode 10 Error: Multiple commands produce for 'app' and 'appex'

Question

I got the recently discussed "Xcode 10 Error: Multiple commands produce..." error, but for the resulting app and appex file of my project. Does anyone have an idea what this means. My project has one app and two extensions (only one is part of the error).

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Prepare build
note: Using new build systemnote: Planning buildnote: Constructing build description

Build system information
error: Multiple commands produce '/Users/xxx/Library/Developer/Xcode/DerivedData/MyApp-enqofdpadskdcgemmhrzsxahnjet/Build/Products/Debug-iphoneos/MyApp Dev.app':
1) Target 'MyApp Dev' has create directory command with output '/Users/xxx/Library/Developer/Xcode/DerivedData/MyApp-enqofdpadskdcgemmhrzsxahnjet/Build/Products/Debug-iphoneos/MyApp Dev.app'
2) That command depends on command in Target 'MyApp Dev': script phase “[CP] Copy Pods Resources”

Build system information
error: Multiple commands produce '/Users/xxx/Library/Developer/Xcode/DerivedData/MyApp-enqofdpadskdcgemmhrzsxahnjet/Build/Products/Debug-iphoneos/MyApp Dev Share Extension.appex':
1) Target 'MyApp Dev Share Extension' has create directory command with output '/Users/xxx/Library/Developer/Xcode/DerivedData/MyApp-enqofdpadskdcgemmhrzsxahnjet/Build/Products/Debug-iphoneos/MyApp Dev Share Extension.appex'
2) That command depends on command in Target 'MyApp Dev Share Extension': script phase “[CP] Copy Pods Resources”

Build system information
warning: ignoring duplicated output file: '/Users/xxx/Library/Developer/Xcode/DerivedData/MyApp-enqofdpadskdcgemmhrzsxahnjet/Build/Products/Debug-iphoneos/MyApp Dev.app' (in target 'MyApp Dev')
Build system information
warning: ignoring duplicated output file: '/Users/xxx/Library/Developer/Xcode/DerivedData/MyApp-enqofdpadskdcgemmhrzsxahnjet/Build/Products/Debug-iphoneos/MyApp Dev Share Extension.appex' (in target 'MyApp Dev Share Extension')

Build failed    18.09.18, 10:28    4.5 seconds

I know I can go back to the legacy build system, but I would prefer using the new and faster build system. Thank you for any help.

Answer 1

In case someone is still struggling with this after updating cocoapods and reinstalling pods:

1. Open Build Phases of the target which gives you problems
2. Open Copy Pods Resources phase.
3. Make sure the Output Files is empty. In my case I had a strange entry ${TARGET_BUILD_DIR}/${UNLOCALIZED_RESOURCES_FOLDER_PATH}. I removed it and the build was successful

Answer 2

Solved my problem by updating Cocoapods from 1.4.0 to 1.5.3

Answer 3

I was able to fix it by opening the Runner workspace project in Xcode 10. Then navigate to File, Workspace Settings and change the build system to Legacy Build System.

Answer 4

My Cocoapod version was already 1.5.3(latest). Just running "pod install" (or "pod install --no-repo-update" if you don't want to update existing pods) solved it for me.