Compile with Xcode 15.1 help

[DarshanNairDiscovery]

From this link, I understand that SKIE is supported only from Xcode 14.3 and newer versions. I added the SKIE plugin to the KMP module, and the XCFramework is generated successfully. However, when integrating it into the consumer iOS application using Xcode 15.1, I encounter the following build error:

Undefined symbols:
 __swift_FORCE_LOAD_$_swiftXPC, referenced from:
   __swift_FORCE_LOAD_$_swiftXPC_$_MultiplatformBoltPlaybackInfoResolver in MultiplatformBoltPlaybackInfoResolver[16](PlayerCommon.BitrateType.o)

Interestingly, when I add the same XCFramework in Xcode 15.4, it works fine. Is there a way to make it compile with Xcode 15.1 or any known issue?

[FilipDolnik]

Hi!

I'm not aware of any existing issue that could cause that so this is most likely a new bug.

We will need to find out a reproducer. Can you please send us the code mentioned in the error message?

• Primarily the PlayerCommon.BitrateType.swift file (likely located in build/skie/$path_to_the_framework/swift/generated)
• The Kotlin code based on which the file was generated. This will likely be the MultiplatformBoltPlaybackInfoResolver class.

Also: What version of Kotlin and SKIE do you have?

[DarshanNairDiscovery]

Hi @FilipDolnik, thanks for your reply.
Since our actual project is a bit longer, I reproduced the issue in a smaller KMP setup with just two small classes. It also generates the same error log at build time:

Ld /Users/danair/Library/Developer/Xcode/DerivedData/TestKMPLinkingIssue-gtmqlpqwtohwlxboxcowjwhkufwc/Build/Products/Debug-iphonesimulator/TestKMPLinkingIssue.app/TestKMPLinkingIssue normal (in target 'TestKMPLinkingIssue' from project 'TestKMPLinkingIssue')
    cd /Users/danair/Desktop/iOSRepository/TestKMPLinkingIssue
    /Applications/Xcode\ copy.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang -Xlinker -reproducible -target x86_64-apple-ios17.5-simulator -isysroot /Applications/Xcode\ copy.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator17.2.sdk -O0 -L/Users/danair/Library/Developer/Xcode/DerivedData/TestKMPLinkingIssue-gtmqlpqwtohwlxboxcowjwhkufwc/Build/Intermediates.noindex/EagerLinkingTBDs/Debug-iphonesimulator -L/Users/danair/Library/Developer/Xcode/DerivedData/TestKMPLinkingIssue-gtmqlpqwtohwlxboxcowjwhkufwc/Build/Products/Debug-iphonesimulator -F/Users/danair/Library/Developer/Xcode/DerivedData/TestKMPLinkingIssue-gtmqlpqwtohwlxboxcowjwhkufwc/Build/Intermediates.noindex/EagerLinkingTBDs/Debug-iphonesimulator -F/Users/danair/Library/Developer/Xcode/DerivedData/TestKMPLinkingIssue-gtmqlpqwtohwlxboxcowjwhkufwc/Build/Products/Debug-iphonesimulator -filelist /Users/danair/Library/Developer/Xcode/DerivedData/TestKMPLinkingIssue-gtmqlpqwtohwlxboxcowjwhkufwc/Build/Intermediates.noindex/TestKMPLinkingIssue.build/Debug-iphonesimulator/TestKMPLinkingIssue.build/Objects-normal/x86_64/TestKMPLinkingIssue.LinkFileList -Xlinker -rpath -Xlinker @executable_path/Frameworks -dead_strip -Xlinker -object_path_lto -Xlinker /Users/danair/Library/Developer/Xcode/DerivedData/TestKMPLinkingIssue-gtmqlpqwtohwlxboxcowjwhkufwc/Build/Intermediates.noindex/TestKMPLinkingIssue.build/Debug-iphonesimulator/TestKMPLinkingIssue.build/Objects-normal/x86_64/TestKMPLinkingIssue_lto.o -Xlinker -export_dynamic -Xlinker -no_deduplicate -Xlinker -objc_abi_version -Xlinker 2 -fobjc-link-runtime -L/Applications/Xcode\ copy.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift/iphonesimulator -L/usr/lib/swift -Xlinker -add_ast_path -Xlinker /Users/danair/Library/Developer/Xcode/DerivedData/TestKMPLinkingIssue-gtmqlpqwtohwlxboxcowjwhkufwc/Build/Intermediates.noindex/TestKMPLinkingIssue.build/Debug-iphonesimulator/TestKMPLinkingIssue.build/Objects-normal/x86_64/TestKMPLinkingIssue.swiftmodule -Xlinker -sectcreate -Xlinker __TEXT -Xlinker __entitlements -Xlinker /Users/danair/Library/Developer/Xcode/DerivedData/TestKMPLinkingIssue-gtmqlpqwtohwlxboxcowjwhkufwc/Build/Intermediates.noindex/TestKMPLinkingIssue.build/Debug-iphonesimulator/TestKMPLinkingIssue.build/TestKMPLinkingIssue.app-Simulated.xcent -Xlinker -sectcreate -Xlinker __TEXT -Xlinker __ents_der -Xlinker /Users/danair/Library/Developer/Xcode/DerivedData/TestKMPLinkingIssue-gtmqlpqwtohwlxboxcowjwhkufwc/Build/Intermediates.noindex/TestKMPLinkingIssue.build/Debug-iphonesimulator/TestKMPLinkingIssue.build/TestKMPLinkingIssue.app-Simulated.xcent.der -framework MultiPlatformPlayerCommon -Xlinker -no_adhoc_codesign -Xlinker -dependency_info -Xlinker /Users/danair/Library/Developer/Xcode/DerivedData/TestKMPLinkingIssue-gtmqlpqwtohwlxboxcowjwhkufwc/Build/Intermediates.noindex/TestKMPLinkingIssue.build/Debug-iphonesimulator/TestKMPLinkingIssue.build/Objects-normal/x86_64/TestKMPLinkingIssue_dependency_info.dat -o /Users/danair/Library/Developer/Xcode/DerivedData/TestKMPLinkingIssue-gtmqlpqwtohwlxboxcowjwhkufwc/Build/Products/Debug-iphonesimulator/TestKMPLinkingIssue.app/TestKMPLinkingIssue

ld: warning: Could not find or use auto-linked library 'swiftXPC': library 'swiftXPC' not found
ld: Undefined symbols:
  __swift_FORCE_LOAD_$_swiftXPC, referenced from:
      __swift_FORCE_LOAD_$_swiftXPC_$_MultiPlatformPlayerCommon in MultiPlatformPlayerCommon[x86_64][24](IosTesting.TrackType.o)
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Attaching the generated IosTesting.TrackType.swift file along with the complete kmp project to reproduce the issue. Also, I have attached the iOS side integration code as well.
As previously mentioned, this issue occurs only with Xcode 15.1, but the same project works fine when run with Xcode 15.4.
iOSSkieError.zip
Using below versions:
Kotlin = 1.9.10
SKIE = 0.8.2

Please let me know if we are using the library incorrectly or if you need any additional information.

[FilipDolnik]

Hi! The zip you sent does not contain all the files needed to build the project. For example the libs.versions.toml file is missing.

However, based on the full error I think the issue might be a mismatch between Xcode versions. The Kotlin compiler probably uses a newer version of Xcode than 15.1. This might not cause an issue with pure Obj-C code but it's a problem for Swift because there is no forward compatibility (see https://developer.apple.com/forums/thread/749540).

Kotlin usually uses the "default" Xcode version so you can check which one it is by running this command: xcode-select -p.

[DarshanNairDiscovery]

Thanks @FilipDolnik!
Oh yeah, I was using 15.4 as a default XCode hence generated XCFramework was not compatible with 15.1 when imported. After setting the default to 15.2 XCode it's working correctly now. Thank you so much for the input here.