Can't build for iOS Simulator when SDK installed with Carthage

[Robert S.138]

Apple broke my Dropbox SDK installation in their latest XCODE 12.0.1.  I was using the Cocoa Pods method ever since Dropbox V2 came out.  So I decided to redo my project using Carthage.  It works fine when building for an iOS device, but fails when building for the simulator.  I don't know how Cocoa Pods handled it.  All I know it that it used to work.  But with Carthage, apparently, the SDK builds a static library for ARM processors only, and the simulator requires X86_64.  By the way, the failure in the Cocoa Pods method was that the Dropbox SDK headers were not found when building for the simulator, even though they were found when building for devices.  So with both Carthage and with Cocoa Pods, I can build for devices but not for the simulator, but for different reasons.  Is there a way with XCODE 12.0.1 to build for the simulator?  (I need to use the latest XCODE because I am debugging an iOS 14 problem which is only supported in XCODE 12.)

[Robert S.138]

In addition to the problems with the Dropbox API installed with Carthage, I even tried making a new project with Cocoa Pods.  In both cases, the XCODE 12 build process crashes whenever one of my application source files imports "ObjectiveDropboxOfficial.h".  Has anyone successfully used XCODE 12 to build a project for the simulator containing the Dropbox API?

[Greg-DB]

Thanks for the report! We'll look into this to see what the issue may be.

To make sure we reproduce the same problem you're seeing though, can you share the relevant error messages you're getting? Thanks in advance! 

[Greg-DB]

It looks like these issues are due to incompatibilies with Xcode 12 in both Cocoapods and Carthage.

For Cocoapods, please refer to this issue: https://github.com/CocoaPods/CocoaPods/issues/9902

For Carthage, please refer to this issue: https://github.com/Carthage/Carthage/issues/3019

[Robert S.138]

Here is the latest minimal failure example:

Start XCODE 12.0.1:  Select "New Project".  Select "App".  Project Name: "TuneLab3"  Create.

This skeleton program builds OK.  Now to manually add Dropbox as a subproject (which also involves Carthage).

Create Cartfile in project root with the following contents:

# ObjectiveDropboxOfficial

github "https://github.com/dropbox/dropbox-sdk-obj-c" ~> 5.0.3

Open a terminal window, navigate to the project root, and do:

carthage update --platform iOS

And this is the output:

*** Fetching dropbox-sdk-obj-c

*** Checking out dropbox-sdk-obj-c at "5.0.3"

*** xcodebuild output can be found in /var/folders/mh/0wpmn3f15r18xmqnrgtyzrgm0000gn/T/carthage-xcodebuild.YEPV7A.log

*** Building scheme "ObjectiveDropboxOfficial iOS" in ObjectiveDropboxOfficial.xcodeproj

Build Failed

Task failed with exit code 1:

/usr/bin/xcrun lipo -create /Users/robertscott/Library/Caches/org.carthage.CarthageKit/DerivedData/12.0.1_12A7300/dropbox-sdk-obj-c/5.0.3/Build/Intermediates.noindex/ArchiveIntermediates/ObjectiveDropboxOfficial\ iOS/IntermediateBuildFilesPath/UninstalledProducts/iphoneos/ObjectiveDropboxOfficial.framework/ObjectiveDropboxOfficial /Users/robertscott/Library/Caches/org.carthage.CarthageKit/DerivedData/12.0.1_12A7300/dropbox-sdk-obj-c/5.0.3/Build/Products/Release-iphonesimulator/ObjectiveDropboxOfficial.framework/ObjectiveDropboxOfficial -output /Users/robertscott/Documents/iOSdev/TuneLab3/Carthage/Build/iOS/ObjectiveDropboxOfficial.framework/ObjectiveDropboxOfficial

This usually indicates that project itself failed to compile. Please check the xcodebuild log for more details: /var/folders/mh/0wpmn3f15r18xmqnrgtyzrgm0000gn/T/carthage-xcodebuild.YEPV7A.log

But when I look at the log file cited, it is an 8 MB file that ends with:

** BUILD SUCCEEDED **

Should I just trust that everything is OK?

[Greg-DB]

Thanks for following up. It looks like this is due to that Carthage issue. We can't officially offer support for Carthage itself as that's not made by Dropbox though, so I'll have to defer to the information in the Carthage issue regarding this. It looks like that's currently still open.

For reference though, one way to check the version of the Dropbox Objective-SDK that is loaded in a project is to check the value of `kDBSDKVersion` in code, which is a constant containing the Dropbox Objective-SDK version number.

[Robert S.138]

Is there a way to add the Dropbox SDK to an XCODE project that does not involve any 3rd party software like Carthage or CocoaPods just by copying source code directly?  Even though the problem I need to debug in iOS 14 has nothing to do with Dropbox, if I can't even build my app for iOS 14 I can't do any debugging on that issue and I can't build for iOS 14 without XCODE 12.

[Greg-DB]

No, unfortunately the only officially supported installation methods for the Dropbox API v2 Objective-C SDK use Cocoapods or Carthage, but I'll pass this along as a feature request. I can't promise if or when that might be implemented though. 

[Robert S.138]

In the meantime perhaps someone at Dropbox could at least try to add the SDK to a new skeleton project using XCODE 12.  The test is to build for both the simulator and a real ARM device.

[Greg-DB]

I'll pass this request along (though we'd also run in to the same issues with Cocoapods/Carthage anyway).

It looks like there are some workarounds available in the Carthage issue while they work to resolve this properly, so you may want to use one of those to get running for now. (Or, likewise use Cocoapods 1.10, which seems to currently be in beta, per the Cocoapods issue.)