Duplicate symbols when installed via Homebrew

[plu]

objc[31962]: Class _TtCs18_EmptyArrayStorage is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftCore.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftCore.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _TtCs24_ContiguousArrayStorage1 is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftCore.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftCore.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _TtCs17_CocoaSetIterator is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftCore.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftCore.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _TtCs24_CocoaDictionaryIterator is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftCore.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftCore.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _TtCs17NonObjectiveCBase is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftCore.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftCore.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _TtCs17_stdlib_AtomicInt is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftCore.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftCore.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _TtCs19_SwiftNativeNSArray is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftCore.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftCore.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _TtCs24_SwiftNativeNSDictionary is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftCore.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftCore.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _TtCs17_SwiftNativeNSSet is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftCore.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftCore.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _TtCs24_SwiftNativeNSEnumerator is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftCore.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftCore.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _TtCs18_SwiftNativeNSData is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftCore.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftCore.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _TtCs26_SwiftNativeNSCharacterSet is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftCore.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftCore.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _TtCs31_stdlib_ReturnAutoreleasedDummy is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftCore.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftCore.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _TtCs20_SwiftNativeNSString is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftCore.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftCore.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _TtCs19_NSContiguousString is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftCore.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftCore.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _TtCs40_SwiftNativeNSArrayWithContiguousStorage is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftCore.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftCore.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _TtCs21_SwiftDeferredNSArray is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftCore.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftCore.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _TtCs27_ContiguousArrayStorageBase is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftCore.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftCore.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _TtCs14_VaListBuilder is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftCore.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftCore.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _TtCs13VaListBuilder is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftCore.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftCore.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _SwiftNativeNSError is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftCore.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftCore.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class SwiftObject is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftCore.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftCore.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _SwiftValue is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftCore.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftCore.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _SwiftNull is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftCore.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftCore.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _SwiftNativeNSArrayBase is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftCore.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftCore.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _SwiftNativeNSDictionaryBase is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftCore.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftCore.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _SwiftNativeNSSetBase is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftCore.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftCore.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _SwiftNativeNSStringBase is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftCore.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftCore.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _SwiftNativeNSEnumeratorBase is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftCore.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftCore.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _SwiftNativeNSDataBase is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftCore.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftCore.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _SwiftNativeNSCharacterSetBase is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftCore.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftCore.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _SwiftNativeNSIndexSetBase is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftCore.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftCore.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _TtC8Dispatch16DispatchWorkItem is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftDispatch.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftDispatch.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _TtC10Foundation15NSSimpleCString is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftFoundation.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftFoundation.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _TtC10Foundation16NSConstantString is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftFoundation.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftFoundation.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _TtC10Foundation25NSFastEnumerationIterator is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftFoundation.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftFoundation.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _TtC10Foundation25_NSErrorRecoveryAttempter is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftFoundation.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftFoundation.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _TtC10Foundation20_SwiftNSCharacterSet is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftFoundation.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftFoundation.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _TtC10Foundation12_SwiftNSData is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftFoundation.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftFoundation.dylib. One of the two will be used. Which one is undefined.
objc[31962]: Class _SwiftTypePreservingNSNumber is implemented in both /usr/local/Cellar/pxctest/0.2.1/libexec/PXCTestKit.framework/Versions/A/Frameworks/libswiftFoundation.dylib and /Applications/Xcode.app/Contents/SharedFrameworks/SourceKit.framework/Versions/A/Frameworks/libswiftFoundation.dylib. One of the two will be used. Which one is undefined.

[JeanMertz]

I'm still seeing this with pxctest, even when using --HEAD with Homebrew.

[RichardGuion]

I just installed using

brew tap plu/pxctest && brew install pxctest

and still seeing:

objc[61825]: Class _TtCs18_EmptyArrayStorage is implemented in both /usr/local/Cellar/pxctest/0.3.3/libexec/Frameworks/PXCTestKit.framework/Versions/A/Frameworks/libswiftCore.dylib (0x10dece990) and /Applications/Xcode.app/Contents/Frameworks/libswiftCore.dylib (0x11160a990). One of the two will be used. Which one is undefined.