title: Add Test Target to existing project in Xcode 6.3
body: <p>Note: this question is related, but the answer given there does not solve the issue for me: <a href="https://stackoverflow.com/questions/28019386/xc-testing-framework-iosxcode-6-1-test-session-exited80-without-checking-in">XC Testing Framework iOS(XCode 6.1) Test session exited(80) without checking in</a></p>
  
  <p>I have existing iOS code, and I want to start writing XCTest cases using my Xcode 6.3. I create a Test Target by clicking on the + in the Test Navigator. A test target is created for me, including a file Tests with unit tests in them. </p>
  
  <p>The test starts greyed out in the Test Navigator (I cannot click cmd+T). </p>
  
  <p><em>Question 1</em>: How can I enable the tests?</p>
  
  <p><strong>EDIT</strong>: The answer is described in this screenshot: <a href="https://www.evernote.com/shard/s4/sh/6a5ca990-d723-46ee-bf77-2cf0ff4e70b2/1a62c472fbbeeffa595fcecd4a9fbbf7" rel="nofollow noreferrer">https://www.evernote.com/shard/s4/sh/6a5ca990-d723-46ee-bf77-2cf0ff4e70b2/1a62c472fbbeeffa595fcecd4a9fbbf7</a>, which I found here: <a href="https://stackoverflow.com/questions/6865735/adding-unit-tests-to-an-already-existing-project">Adding Unit Tests to an already existing project?</a></p>
  
  <p>In my project settings, I have the following settings for my production target (legacy):
  <img src="https://i.stack.imgur.com/ipscO.png" alt="Project settings production target">
  And the following settings for my test target (auto generated):
  <img src="https://i.stack.imgur.com/3fjHS.png" alt="Project settings test target"></p>
  
  <p>If I run my test anyway manually by clicking on the Play button in the Test Navigator, I receive the following extensive error messages.</p>
  
  <pre><code>Warning: Error creating LLDB target at path '/Users/erwin/Library/Developer/Xcode/DerivedData/NyonOrder-bzkqdvtkegbjpuccyzmrgprbjqgm/Build/Products/Debug-iphonesimulator/OrderWriter.app'- using an empty LLDB target which can cause slow memory reads from remote devices.
  IDEBundleInjection.c: Error 3585 loading bundle '/Users/erwin/Library/Developer/Xcode/DerivedData/NyonOrder-bzkqdvtkegbjpuccyzmrgprbjqgm/Build/Products/Debug-iphonesimulator/NyonOrderTests.xctest': The bundle “NyonOrderTests” couldn’t be loaded because it doesn’t contain a version for the current architecture.
  DevToolsBundleInjection environment:
  XCInjectDiagnostics: (null)
  XCInjectBundleInto: /Users/erwin/Library/Developer/Xcode/DerivedData/NyonOrder-bzkqdvtkegbjpuccyzmrgprbjqgm/Build/Products/Debug-iphonesimulator/OrderWriter.app/OrderWriter
  XCInjectBundle: /Users/erwin/Library/Developer/Xcode/DerivedData/NyonOrder-bzkqdvtkegbjpuccyzmrgprbjqgm/Build/Products/Debug-iphonesimulator/NyonOrderTests.xctest
  TestBundleLocation: /Users/erwin/Library/Developer/Xcode/DerivedData/NyonOrder-bzkqdvtkegbjpuccyzmrgprbjqgm/Build/Products/Debug-iphonesimulator/NyonOrderTests.xctest
  TMPDIR: /Users/erwin/Library/Developer/CoreSimulator/Devices/7094B929-04BD-459E-8E83-BDF9CBFA397A/data/Containers/Data/Application/B02B9956-754B-4663-9BC2-7191B0C2BFFE/tmp
  DYLD_LIBRARY_PATH: /Users/erwin/Library/Developer/Xcode/DerivedData/NyonOrder-bzkqdvtkegbjpuccyzmrgprbjqgm/Build/Products/Debug-iphonesimulator
  DYLD_INSERT_LIBRARIES: /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/Library/PrivateFrameworks/IDEBundleInjection.framework/IDEBundleInjection
  DYLD_FRAMEWORK_PATH: /Users/erwin/Library/Developer/Xcode/DerivedData/NyonOrder-bzkqdvtkegbjpuccyzmrgprbjqgm/Build/Products/Debug-iphonesimulator
  DYLD_FALLBACK_LIBRARY_PATH: /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator.sdk/usr/lib
  DYLD_FALLBACK_FRAMEWORK_PATH: /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/Library/Frameworks
  
  
  *** Test session exited(80) without checking in. Executable does not provide an architecture compatible with the current process. If you believe this error represents a bug, please attach the log file at /var/folders/cn/sfcysstx0zxb13qzdj35rh040000gn/T/com.apple.dt.XCTest-status/Session-2015-04-10_13:58:25-8ifyOV.log
  </code></pre>
  
  <p><em>Question 2</em>: Which settings do I additionally have to check/change to be able to run tests?</p>
  
  <p><strong>EDIT</strong> Adding arm64 to the production target valid architecture solved this particular error. Is this dangerous to add?</p>