113 duplicate symbols for architecture x86_64

[vipinsaini0]

Checklist before submitting a bug report

• I've updated to the latest released version of the SDK
• I've searched for existing GitHub issues
• I've looked for existing answers on Stack Overflow, the Facebook Developer Community Forum and the Facebook Developers Group
• I've read the Code of Conduct
• This issue is not security related and can safely be disclosed publicly on GitHub

Xcode version

12.5.1

Facebook iOS SDK version

12.2.0

Dependency Manager

SPM

SDK Framework

Login

Goals

User login in my app by fb login.

Expected results

App run and get user profile details.

Actual results

app run (build) failed.

Steps to reproduce

update swift package from 12.1.0 to 12.2.0. once finished run the app, and getting failed the build.

Code samples & details

No response

[vipinsaini0]

Hi @jawwad @KylinChang , Can you please check and help in it?

[jawwad]

@vipinsaini0 - Hmm, that's weird, maybe a caching issue?

Could you try the following and let me know if it fixes it?

rm -rf ~/Library/Caches/org.swift.swiftpm
rm -rf ~/Library/Developer/Xcode/DerivedData

If not, could you share a bit more about your setup and what packages you are including?

[rromanchuk]

@jawwad just got this as well when pinning 12.2.0 with all the usual resolution steps to no avail. Let me dig in with trial and error. I have multiple targets and utilize FacebookAEM which i see some activity on the changelog. Going to unwind and just link Core then step through it.

[rromanchuk]

Just looking stdout looks like it's between FBSDKCoreKit and FBAEMKit such as FBSDKCoreKit.framework/FBSDKCoreKit(FBAEMAdvertiserMultiEntryRule.o) and FBAEMKit.framework/FBAEMKit(FBAEMAdvertiserMultiEntryRule.o)

./DerivedData/App/Build/Products/Debug-iphoneos/FBSDKCoreKit.framework/FBSDKCoreKit(FBAEMAdvertiserMultiEntryRule.o)
./DerivedData/App/Build/Products/Debug-iphoneos/FBAEMKit.framework/FBAEMKit(FBAEMAdvertiserMultiEntryRule.o)

[rromanchuk]

OK got it building again by selecting my target and adding only FacebookBasics and FacebookAEM which i just sort of guessed after looking at Package.swift#L160 and ignoring https://developers.facebook.com/docs/ios/getting-started (which i usually do)

Not it, if i change build target/device everything implodes. It certainly feels like an insidious module cache issue

PS broken links
https://developers.facebook.com/docs/app-ads/formats/mobile-ads (https://developers.facebook.com/docs/ios under ios features)
https://developers.facebook.com/docs/app-ads/measuring (https://developers.facebook.com/docs/app-events/best-practices first link)

[dejiapps]

I am having this issue too.

[joesus]

Going to unwind and just link Core then step through it.

@rromanchuk what do you mean by this. Trying to reproduce the issue and coming up short. Can this be replicated in a minimal sample project?

[rromanchuk]

I'm going to remove everything and add back incrementally so i can at least step through compilation errors and pinpoint the moment it repos. It's hard to create a minimal project, because even on File -> New Project the diff on build settings is already a massive departure, which i wouldnt be surprised if i had some bespoke setting causing the issue.

Only consistent thing i have right now is a the dupe is between AEM and Core

❌ duplicate symbol 'OBJC_CLASS$_FBAEMAdvertiserMultiEntryRule' in

FBAEMKit(FBAEMAdvertiserMultiEntryRule.o)
FBSDKCoreKit(FBAEMAdvertiserMultiEntryRule.o)

[rromanchuk]

Ok, i got it building again by re-aligning some of build settings closer to what X-Code generates after a new ios/storyboard project. I don't have a great a control, because of how long purging cache + rebuild takes, but some of the changes i made are below. My guess is other linker flags.

• removed linker flag -objc (N/A, old legacy requirement for for pre spm sdks)
• Bump 13 up to 14.0 as my deployment target
• explicit specify gnu/libc++ instead of compiler default
• Always search user paths to NO

I've built to both targets, device, sim successfully 🤷

TLDR: To fix, grep the project file for OTHER_LDFLAGS = "-ObjC"; and remove it

[rromanchuk]

@joesus OK, i got the repro for you https://github.com/rromanchuk/fb-duplicate-syms

It's 100% -ObjC. File -> new project -> swift/storyboard -> add the linker flag and you can repro the same error. That makes a little more sense, especially since older projects are likely to have this legacy cruft sitting around from popular SDKs like firebase on cocoapods

// AppDelegate.swift
import UIKit
import FacebookCore
import FacebookLogin
import FacebookShare
// ....

[vipinsaini0]

rm -rf ~/Library/Developer/Xcode/DerivedData

@vipinsaini0 - Hmm, that's weird, maybe a caching issue?

Could you try the following and let me know if it fixes it?

rm -rf ~/Library/Caches/org.swift.swiftpm
rm -rf ~/Library/Developer/Xcode/DerivedData

If not, could you share a bit more about your setup and what packages you are including?

After run this two command, still same error.
I used coreKit and LoginKit libraries.
If I downgrade 12.2.0 -> 12.1.0 then no error show.

• Now I tried with pods after run this two command then run successfully.

but getting error log -

-canOpenURL: failed for URL: "fbapi:/" - error: "The operation couldn’t be completed. (OSStatus error -10814.)"

[vipinsaini0]

rm -rf ~/Library/Developer/Xcode/DerivedData

@vipinsaini0 - Hmm, that's weird, maybe a caching issue?
Could you try the following and let me know if it fixes it?

rm -rf ~/Library/Caches/org.swift.swiftpm
rm -rf ~/Library/Developer/Xcode/DerivedData

If not, could you share a bit more about your setup and what packages you are including?

After run this two command, still same error. I used coreKit and LoginKit libraries. If I downgrade 12.2.0 -> 12.1.0 then no error show.

• Now I tried with pods after run this two command then run successfully.

but getting error log -

-canOpenURL: failed for URL: "fbapi:/" - error: "The operation couldn’t be completed. (OSStatus error -10814.)"

By adding below fb notification, now working fine. Thank you!

NotificationCenter.default.addObserver(forName: .AccessTokenDidChange, object: nil, queue: OperationQueue.main) { (notification) in }

[joesus]

Seems like there were two issues here:

1. Including the linker flag OTHER_LDFLAGS = "-ObjC"; caused a duplicate symbol failure. This is something to explore since I'm not entirely sure why this would happen. In either case we can add a note to changelog about this.

2. The warning:

NotificationCenter.default.addObserver(forName: .AccessTokenDidChange, object: nil, queue: OperationQueue.main) { (notification) in }

This seems like a separate issue. My guess is that the SDK isn't being initialized correctly. That observer is added when the FBSDKAccessTokenExpirer is created FBSDKAccessTokenExpirer.m#L30 by the initializer for FBSDKApplicationDelegate see: FBSDKApplicationDelegate.m#L212.

Please open a new issue if initializing the SDK according to the getting started instructions does not resolve the issue. You should not need to add that observer yourself.

Closing since it seems like the issue is resolved. Thank you for bringing this up and for helping provide a useful repro sample!!!

[joesus]

On second thought. Will leave this open for now and work on a patch fix since this is definitely a breaking change.

[jawwad]

@vipinsaini0, @rromanchuk, @dejiapps - We just released v12.2.1 which should fix this issue.

Special thanks to @rromanchuk for troubleshooting and providing a sample project and to @joesus for fixing the issue!