title: Xcode 10b5 - duplicate symbol linker error, can't compile with Crashlytics
body: <p>I'm trying to compile my project, which has both Firebase, Crashlytics/Fabric, and a bunch of other stuff, with Xcode 10 beta 5.
  It fails during linking with these errors:</p>
  
  <pre><code>Ld /Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/appname.app/appname normal arm64 (in target: appname)
          cd /Users/Username/iPhone-dev/appname
          export IPHONEOS_DEPLOYMENT_TARGET=9.0
          /Users/Username/Downloads/Xcode-beta.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang -arch arm64 -isysroot /Users/Username/Downloads/Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS12.0.sdk -L/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/AFNetworking -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/Actions -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/AppAuth -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/Bluepeer -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/Bolts -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/CocoaAsyncSocket -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/CocoaLumberjack -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/Color-Picker-for-iOS -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/DNPWPSPrinter -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/DataCompression -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/EOSFTPServer -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/FBSDKCoreKit -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/FBSDKLoginKit -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/FastttCamera -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/FirebaseAuth -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/FirebaseCore -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/FirebaseDatabase -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/FirebaseStorage -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/GTMAppAuth -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/GTMSessionFetcher -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/Gloss -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/GoldRaccoon -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/GoogleToolboxForMac -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/HHServices -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/JPSVolumeButtonHandler -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/M13BadgeView -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/ObjectiveDropboxOfficial -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/PhoneNumberKit -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/Protobuf -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/TPCircularBuffer -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/leveldb-library -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/nanopb -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/upnpx -F/Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/xaphodObjCUtils -F/Users/Username/iPhone-dev/appname/Pods/Crashlytics/iOS -F/Users/Username/iPhone-dev/appname/Pods/Fabric/iOS -F/Users/Username/iPhone-dev/appname/Pods/FirebaseABTesting/Frameworks -F/Users/Username/iPhone-dev/appname/Pods/FirebaseAnalytics/Frameworks -F/Users/Username/iPhone-dev/appname/Pods/FirebaseDynamicLinks/Frameworks -F/Users/Username/iPhone-dev/appname/Pods/FirebaseInstanceID/Frameworks -F/Users/Username/iPhone-dev/appname/Pods/FirebaseRemoteConfig/Frameworks -F/Users/Username/iPhone-dev/appname/Pods/TwitterCore/iOS -F/Users/Username/iPhone-dev/appname/Pods/TwitterKit/iOS -F/Users/Username/iPhone-dev/appname/cascablecore-binaries/Binaries/iOS -filelist /Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Intermediates.noindex/appname.build/Debug-iphoneos/appname.build/Objects-normal/arm64/appname.LinkFileList -Xlinker -rpath -Xlinker @executable_path/Frameworks -Xlinker -rpath -Xlinker @loader_path/Frameworks -Xlinker -rpath -Xlinker @executable_path/Frameworks -miphoneos-version-min=9.0 -dead_strip -Xlinker -object_path_lto -Xlinker /Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Intermediates.noindex/appname.build/Debug-iphoneos/appname.build/Objects-normal/arm64/appname_lto.o -Xlinker -export_dynamic -Xlinker -no_deduplicate -fobjc-arc -fobjc-link-runtime -L/Users/Username/Downloads/Xcode-beta.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift/iphoneos -Xlinker -add_ast_path -Xlinker /Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Intermediates.noindex/appname.build/Debug-iphoneos/appname.build/Objects-normal/arm64/appname.swiftmodule -ObjC -lc++ -licucore -lsqlite3 -lz -framework AFNetworking -framework AVFoundation -framework Accounts -framework Actions -framework AppAuth -framework AssetsLibrary -framework Bluepeer -framework Bolts -framework CFNetwork -framework CocoaAsyncSocket -framework CocoaLumberjack -framework Color_Picker_for_iOS -framework CoreData -framework CoreGraphics -framework CoreMedia -framework CoreText -framework Crashlytics -framework DNPWPSPrinter -framework DataCompression -framework EOSFTPServer -framework FBSDKCoreKit -framework FBSDKLoginKit -framework Fabric -framework FastttCamera -framework FirebaseABTesting -framework FirebaseAnalytics -framework FirebaseAuth -framework FirebaseCore -framework FirebaseCoreDiagnostics -framework FirebaseDatabase -framework FirebaseDynamicLinks -framework FirebaseInstanceID -framework FirebaseNanoPB -framework FirebaseRemoteConfig -framework FirebaseStorage -framework Foundation -framework GTMAppAuth -framework GTMSessionFetcher -framework Gloss -framework GoldRaccoon -framework GoogleToolboxForMac -framework HHServices -framework JPSVolumeButtonHandler -framework M13BadgeView -framework MessageUI -framework MobileCoreServices -framework ObjectiveDropboxOfficial -framework PhoneNumberKit -framework Protobuf -framework QuartzCore -framework SafariServices -framework Security -framework Social -framework StoreKit -framework SystemConfiguration -framework TPCircularBuffer -framework TwitterCore -framework TwitterKit -framework UIKit -framework leveldb -framework nanopb -framework upnpx -framework xaphodObjCUtils -weak_framework WebKit -ObjC -lc++ -licucore -lsqlite3 -lz -lctemplate-ios -letpan-ios -lxml2 -lsasl2 -liconv -ltidy -lz -lc++ -lresolv -stdlib=libc++ -ObjC /Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/libMailCore-ios.a -framework SafariServices -framework CascableCore -framework Security -framework CFNetwork -framework MessageUI -framework StoreKit -framework GameKit -framework StopKit -framework Pods_appname -Xlinker -dependency_info -Xlinker /Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Intermediates.noindex/appname.build/Debug-iphoneos/appname.build/Objects-normal/arm64/appname_dependency_info.dat -o /Users/Username/Library/Developer/Xcode/DerivedData/appname-lastnamepjksdzfewpftlvqzuglaxplu/Build/Products/Debug-iphoneos/appname.app/appname
  
      duplicate symbol l086 in:
          /Users/Username/iPhone-dev/appname/Pods/Crashlytics/iOS/Crashlytics.framework/Crashlytics(CLSFileManager.o)
          /Users/Username/iPhone-dev/appname/Pods/Crashlytics/iOS/Crashlytics.framework/Crashlytics(CLSInternalReport.o)
      duplicate symbol l087 in:
          /Users/Username/iPhone-dev/appname/Pods/Crashlytics/iOS/Crashlytics.framework/Crashlytics(CLSFileManager.o)
          /Users/Username/iPhone-dev/appname/Pods/Crashlytics/iOS/Crashlytics.framework/Crashlytics(CLSInternalReport.o)
      duplicate symbol l088 in:
          /Users/Username/iPhone-dev/appname/Pods/Crashlytics/iOS/Crashlytics.framework/Crashlytics(CLSSettings.o)
          /Users/Username/iPhone-dev/appname/Pods/Crashlytics/iOS/Crashlytics.framework/Crashlytics(CLSInternalReport.o)
  ....&lt;many more omitted&gt;
  </code></pre>
  
  <p>What's the trick to get Google Fabric / Crashlytics working with Xcode 10?</p>
  
  <p><strong>Edit:</strong> Thanks to all who have commented so far. What i've tried so far:</p>
  
  <ul>
  <li>tried reinstalling the pods / clearing pod caches</li>
  <li>tried cleaning build folder, then restarting xcode</li>
  <li>tried playing with -ObjC linker flag. It does indeed look like this flag has something to do with the issue, but unfortunately I need this flag active as I use objective-c frameworks that have static categories on classes</li>
  </ul>