Unity iOS Builds Failing in Xcode 26

[mrcarriere]

Summarize the bug:
A clear and concise summary of the issue.

Our builds are currently failing with the public release of Xcode 26.

Observed problem
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Upon building in Xcode, we receive the failure:
Assertion failed: (it != _dylibToOrdinal.end()), function dylibToOrdinal, file OutputFile.cpp, line 5196.

If we remove the flag -ld_classic, the build succeeds and Vuforia continues to work (in our use case) with this change.

Vuforia is the culprit for this flag being added, as it does so in PostProcessiOSBuild in the Vuforia.Unity.Editor.dll in Vuforia/Plugins/Managed/Editor

Expected result
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Builds succeed in the latest public release of Xcode.

Other observations
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Reproducible steps
Steps to reproduce the behavior:

1. Build a project with Vuforia on the latest release of Xcode, Xcode 26.

Affected Vuforia Engine version:

v11.4.4

Affected platform:

• Workstation OS: macOS
• Platform Unity
• Platform version 6000.0.58f1

Affected device:

N/A

Screenshots / Video Recordings
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N/A

Affected database
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N/A

Device or platform logs
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Showing Recent Messages

ld: warning: -ld_classic is deprecated and will be removed in a future release
0 0x100bc1788 __assert_rtn + 160
1 0x100bc4570 ld::tool::SymbolTableAtom<x86_64>::classicOrdinalForProxy(ld::Atom const*) (.cold.3) + 0
2 0x100afbdb0 ld::tool::SymbolTableAtom<x86_64>::classicOrdinalForProxy(ld::Atom const*) + 172
3 0x100afcc24 ld::tool::SymbolTableAtom::addImport(ld::Atom const*, ld::tool::StringPoolAtom*) + 140
4 0x100afe508 ld::tool::SymbolTableAtom::encode() + 396
5 0x100af03b0 ___ZN2ld4tool10OutputFile20buildLINKEDITContentERNS_8InternalE_block_invoke.413 + 36
6 0x186b63b2c _dispatch_call_block_and_release + 32
7 0x186b7d85c _dispatch_client_callout + 16
8 0x186b9a4cc _dispatch_channel_invoke.cold.5 + 92
9 0x186b75fa4 _dispatch_root_queue_drain + 736
10 0x186b765d4 _dispatch_worker_thread2 + 156
11 0x186d17e28 _pthread_wqthread + 232
A linker snapshot was created at:
/tmp/UnityFramework-2025-09-22-074910.ld-snapshot
ld: Assertion failed: (it != _dylibToOrdinal.end()), function dylibToOrdinal, file OutputFile.cpp, line 5196.
clang++: error: linker command failed with exit code 1 (use -v to see invocation)

-ld_classic is deprecated and will be removed in a future release

Assertion failed: (it != _dylibToOrdinal.end()), function dylibToOrdinal, file OutputFile.cpp, line 5196.

Workaround
Is there currently a workaround that you're using?

Remove -ld_classic from the Xcode Project manually.

Additional comments
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[ptc-emaggio]

Hi @mrcarriere thanks for the report. We are looking into the issue.

[ptc-pmessenger]

Hi @mrcarriere, do you have "Treat warnings as errors" on in your Xcode project? The flag is added for backwards compatibility reasons by Vuforia and will eventually be removed. I've tried to reproduce your issue and am getting only a warning, however I can build fine.

[mrcarriere]

@ptc-pmessenger No, we don't

While this may not be the sole issue of Vuforia in the sense that a basic Vuforia project doesn't create this issue, your plugin is enabling a compiler definition that causes it. (Apple recommends against this practice.)

We had to create a post build processor to forcibly remove this in order to successfully build.