title: Static Linking with Swift, XCode6-Beta
body: <p>I've been experimenting with porting an Obj-C library to Swift, and I've run into a problem where the linker fails to build a static library when Swift code is in the project.</p>
  
  <p>As a minimal reproducer, go into XCode6 and create a new iOS Static Library. It'll give you a project with a blank .h and .m file. This will compile fine. Then, add a new .swift file to the project (with or without creating a header bridge). This too <em>should</em> compile fine, but instead it fails during linking:</p>
  
  <pre><code>Libtool /Users/alexkarantza/Library/Developer/Xcode/DerivedData/Test-alenfoymgkewlghfjjvizjjuvign/Build/Products/Debug-iphonesimulator/libTest.a normal i386
      cd /Users/alexkarantza/Workspace/Test
      export IPHONEOS_DEPLOYMENT_TARGET=8.0
      export PATH="/Applications/Xcode6-Beta.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin:/Applications/Xcode6-Beta.app/Contents/Developer/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin"
      /Applications/Xcode6-Beta.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/libtool -static -arch_only i386 -syslibroot /Applications/Xcode6-Beta.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator8.0.sdk -L/Users/alexkarantza/Library/Developer/Xcode/DerivedData/Test-alenfoymgkewlghfjjvizjjuvign/Build/Products/Debug-iphonesimulator -filelist /Users/alexkarantza/Library/Developer/Xcode/DerivedData/Test-alenfoymgkewlghfjjvizjjuvign/Build/Intermediates/Test.build/Debug-iphonesimulator/Test.build/Objects-normal/i386/Test.LinkFileList -ObjC -L/Applications/Xcode6-Beta.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift/iphonesimulator -Xlinker -rpath -Xlinker /Applications/Xcode6-Beta.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift/iphonesimulator -Xlinker -force_load -Xlinker /Applications/Xcode6-Beta.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/arc/libarclite_iphonesimulator.a -Xlinker -sectalign -Xlinker __SWIFT -Xlinker __ast -Xlinker 4 -Xlinker -sectcreate -Xlinker __SWIFT -Xlinker __ast -Xlinker /Users/alexkarantza/Library/Developer/Xcode/DerivedData/Test-alenfoymgkewlghfjjvizjjuvign/Build/Intermediates/Test.build/Debug-iphonesimulator/Test.build/Objects-normal/i386/Test.swiftmodule -o /Users/alexkarantza/Library/Developer/Xcode/DerivedData/Test-alenfoymgkewlghfjjvizjjuvign/Build/Products/Debug-iphonesimulator/libTest.a
  
  error: /Applications/Xcode6-Beta.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/libtool: unknown option character `X' in: -Xlinker
  Usage: /Applications/Xcode6-Beta.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/libtool -static [-] file [...] [-filelist listfile[,dirname]] [-arch_only arch] [-sacLT] [-no_warning_for_no_symbols]
  Usage: /Applications/Xcode6-Beta.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/libtool -dynamic [-] file [...] [-filelist listfile[,dirname]] [-arch_only arch] [-o output] [-install_name name] [-compatibility_version #] [-current_version #] [-seg1addr 0x#] [-segs_read_only_addr 0x#] [-segs_read_write_addr 0x#] [-seg_addr_table &lt;filename&gt;] [-seg_addr_table_filename &lt;file_system_path&gt;] [-all_load] [-noall_load]
  </code></pre>
  
  <p>This happens if I'm targeting the simulator or the device. It looks like perhaps having the Swift file in the project is causing it to use linker options normally reserved for executables, even though the target is a static library? I don't know enough about the build options to know if this is a bug in the beta, or some option I should be configuring. It seems questionable that the build would legitimately fail on such a trivial example. Any thoughts?</p>