xcode compilation error: Showing Recent Errors Only Undefined symbol: Swift._ArrayBuffer._copyContents(initializing: ...

[Larens94]

Showing Recent Errors Only Undefined symbol: Swift._ArrayBuffer._copyContents(initializing: Swift.UnsafeMutableBufferPointer) -> (Swift.IndexingIterator<Swift._ArrayBuffer>, Swift.Int)

[Jonovono]

I am getting this too :(

[jayeshkarma100]

I also had this issue and asked about it on the Swift forums. The cause is trying to link against an older Swift runtime while targeting a newer version of the OS.
You should be able to just remove those LIBRARY_SEARCH_PATH entries entirely (or just leave $(inherited)) and that will fix the problem. This is a bug in the ReactNative template for iOS.
As mentioned in the above Swift forums thread:
You shouldn't need to add the toolchain library paths to LIBRARY_SEARCH_PATHS yourself, because Xcode will automatically include those libraries if your minimum deployment target is old enough to need them.

[jayeshkarma100]

main issue with Xcode12.5 just a simple thing download Xcode 12.0.1 and work on it

[anatooly]

@Larens94 check this #153 (comment)

[ghost]

I also had this issue and asked about it on the Swift forums. The cause is trying to link against an older Swift runtime while targeting a newer version of the OS.
You should be able to just remove those LIBRARY_SEARCH_PATH entries entirely (or just leave $(inherited)) and that will fix the problem. This is a bug in the ReactNative template for iOS.
As mentioned in the above Swift forums thread:
You shouldn't need to add the toolchain library paths to LIBRARY_SEARCH_PATHS yourself, because Xcode will automatically include those libraries if your minimum deployment target is old enough to need them.

@jayeskarma100 How does one go about removing the LIBRARY_SEARCH_PATHS as you mentioned?

[viktorRot]

Here it is explained how to modify LIBRARY_SEARCH_PATHS: DataDog/dd-sdk-reactnative#41 (comment)

Worked great for me.