title: What do these 15 apple mach o linker error means
body: <p><img src="https://i.stack.imgur.com/96nF9.png" alt="A lot of errors here..."></p>
  
  <p>And this:</p>
  
  <pre><code>Ld /Users/davidraijmakers/Library/Developer/Xcode/DerivedData/Scanner-bbwbbvayxxnrhwdsgbkvibplofyw/Build/Products/Debug-iphoneos/Scanner.app/Scanner normal armv7
      cd /Users/davidraijmakers/Documents/xcodezooi/Scanner
      setenv IPHONEOS_DEPLOYMENT_TARGET 6.0
      setenv PATH "/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin:/Applications/Xcode.app/Contents/Developer/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin"
      /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++ -arch armv7 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS6.0.sdk -L/Users/davidraijmakers/Library/Developer/Xcode/DerivedData/Scanner-bbwbbvayxxnrhwdsgbkvibplofyw/Build/Products/Debug-iphoneos -L/Users/davidraijmakers/Documents/xcodezooi/Scanner/Scanner/ScanditSDK -F/Users/davidraijmakers/Library/Developer/Xcode/DerivedData/Scanner-bbwbbvayxxnrhwdsgbkvibplofyw/Build/Products/Debug-iphoneos -filelist /Users/davidraijmakers/Library/Developer/Xcode/DerivedData/Scanner-bbwbbvayxxnrhwdsgbkvibplofyw/Build/Intermediates/Scanner.build/Debug-iphoneos/Scanner.build/Objects-normal/armv7/Scanner.LinkFileList -dead_strip -fobjc-link-runtime -stdlib=libc++ -miphoneos-version-min=6.0 -liconv -lz -framework CoreVideo -framework AudioToolbox -framework AVFoundation -framework CoreMedia -framework QuartzCore -framework SystemConfiguration -framework UIKit -framework Foundation -framework CoreGraphics -lscanditsdk-iphone-2.2.5 -o /Users/davidraijmakers/Library/Developer/Xcode/DerivedData/Scanner-bbwbbvayxxnrhwdsgbkvibplofyw/Build/Products/Debug-iphoneos/Scanner.app/Scanner
  
  Undefined symbols for architecture armv7:
    "std::basic_ostream&lt;char, std::char_traits&lt;char&gt; &gt;&amp; std::operator&lt;&lt;&lt;std::char_traits&lt;char&gt; &gt;(std::basic_ostream&lt;char, std::char_traits&lt;char&gt; &gt;&amp;, char const*)", referenced from:
        l1348 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1486 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1585 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1600 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1602 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1655 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
    "std::basic_string&lt;char, std::char_traits&lt;char&gt;, std::allocator&lt;char&gt; &gt;::basic_string(char const*, std::allocator&lt;char&gt; const&amp;)", referenced from:
        l1241 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
    "std::ios_base::Init::Init()", referenced from:
        l1670 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1671 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1672 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1673 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1674 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1675 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1676 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        ...
    "std::__throw_length_error(char const*)", referenced from:
        std::vector&lt;zxing::Ref&lt;zxing::datamatrix::Version&gt;, std::allocator&lt;zxing::Ref&lt;zxing::datamatrix::Version&gt; &gt; &gt;::_M_insert_aux(__gnu_cxx::__normal_iterator&lt;zxing::Ref&lt;zxing::datamatrix::Version&gt;*, std::vector&lt;zxing::Ref&lt;zxing::datamatrix::Version&gt;, std::allocator&lt;zxing::Ref&lt;zxing::datamatrix::Version&gt; &gt; &gt; &gt;, zxing::Ref&lt;zxing::datamatrix::Version&gt; const&amp;) in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        std::vector&lt;zxing::datamatrix::ECB*, std::allocator&lt;zxing::datamatrix::ECB*&gt; &gt;::_M_insert_aux(__gnu_cxx::__normal_iterator&lt;zxing::datamatrix::ECB**, std::vector&lt;zxing::datamatrix::ECB*, std::allocator&lt;zxing::datamatrix::ECB*&gt; &gt; &gt;, zxing::datamatrix::ECB* const&amp;) in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        std::vector&lt;zxing::Ref&lt;zxing::qrcode::QRCodeVersion&gt;, std::allocator&lt;zxing::Ref&lt;zxing::qrcode::QRCodeVersion&gt; &gt; &gt;::_M_insert_aux(__gnu_cxx::__normal_iterator&lt;zxing::Ref&lt;zxing::qrcode::QRCodeVersion&gt;*, std::vector&lt;zxing::Ref&lt;zxing::qrcode::QRCodeVersion&gt;, std::allocator&lt;zxing::Ref&lt;zxing::qrcode::QRCodeVersion&gt; &gt; &gt; &gt;, zxing::Ref&lt;zxing::qrcode::QRCodeVersion&gt; const&amp;) in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        std::vector&lt;zxing::qrcode::ECB*, std::allocator&lt;zxing::qrcode::ECB*&gt; &gt;::_M_insert_aux(__gnu_cxx::__normal_iterator&lt;zxing::qrcode::ECB**, std::vector&lt;zxing::qrcode::ECB*, std::allocator&lt;zxing::qrcode::ECB*&gt; &gt; &gt;, zxing::qrcode::ECB* const&amp;) in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        std::vector&lt;zxing::Ref&lt;zxing::qrcode::DataMask&gt;, std::allocator&lt;zxing::Ref&lt;zxing::qrcode::DataMask&gt; &gt; &gt;::_M_insert_aux(__gnu_cxx::__normal_iterator&lt;zxing::Ref&lt;zxing::qrcode::DataMask&gt;*, std::vector&lt;zxing::Ref&lt;zxing::qrcode::DataMask&gt;, std::allocator&lt;zxing::Ref&lt;zxing::qrcode::DataMask&gt; &gt; &gt; &gt;, zxing::Ref&lt;zxing::qrcode::DataMask&gt; const&amp;) in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        std::vector&lt;zxing::qrcode::AlignmentPattern*, std::allocator&lt;zxing::qrcode::AlignmentPattern*&gt; &gt;::_M_insert_aux(__gnu_cxx::__normal_iterator&lt;zxing::qrcode::AlignmentPattern**, std::vector&lt;zxing::qrcode::AlignmentPattern*, std::allocator&lt;zxing::qrcode::AlignmentPattern*&gt; &gt; &gt;, zxing::qrcode::AlignmentPattern* const&amp;) in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        std::vector&lt;zxing::Ref&lt;zxing::qrcode::FinderPattern&gt;, std::allocator&lt;zxing::Ref&lt;zxing::qrcode::FinderPattern&gt; &gt; &gt;::_M_insert_aux(__gnu_cxx::__normal_iterator&lt;zxing::Ref&lt;zxing::qrcode::FinderPattern&gt;*, std::vector&lt;zxing::Ref&lt;zxing::qrcode::FinderPattern&gt;, std::allocator&lt;zxing::Ref&lt;zxing::qrcode::FinderPattern&gt; &gt; &gt; &gt;, zxing::Ref&lt;zxing::qrcode::FinderPattern&gt; const&amp;) in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        ...
    "std::string::append(char const*, unsigned long)", referenced from:
        l1598 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
    "std::string::_Rep::_S_empty_rep_storage", referenced from:
        l1604 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
    "std::basic_ostream&lt;char, std::char_traits&lt;char&gt; &gt;&amp; std::__ostream_insert&lt;char, std::char_traits&lt;char&gt; &gt;(std::basic_ostream&lt;char, std::char_traits&lt;char&gt; &gt;&amp;, char const*, int)", referenced from:
        l1481 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1482 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1483 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1484 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1485 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
    "std::basic_string&lt;char, std::char_traits&lt;char&gt;, std::allocator&lt;char&gt; &gt;::~basic_string()", referenced from:
        l1243 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1244 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1245 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1348 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1477 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1585 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1600 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        ...
    "std::basic_ostringstream&lt;char, std::char_traits&lt;char&gt;, std::allocator&lt;char&gt; &gt;::basic_ostringstream(std::_Ios_Openmode)", referenced from:
        l1348 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1480 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1585 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1600 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1602 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1655 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
    "std::ios_base::Init::~Init()", referenced from:
        l1670 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1671 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1672 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1673 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1674 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1675 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1676 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        ...
    "std::basic_stringbuf&lt;char, std::char_traits&lt;char&gt;, std::allocator&lt;char&gt; &gt;::str() const", referenced from:
        l1348 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1480 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1585 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1600 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1602 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1655 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
    "std::basic_string&lt;char, std::char_traits&lt;char&gt;, std::allocator&lt;char&gt; &gt;::basic_string(std::string const&amp;)", referenced from:
        l1378 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        zxing::Exception::Exception(zxing::Exception const&amp;) in libscanditsdk-iphone-2.2.5.a(mirasense.o)
    "std::basic_ostringstream&lt;char, std::char_traits&lt;char&gt;, std::allocator&lt;char&gt; &gt;::~basic_ostringstream()", referenced from:
        l1348 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1480 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1585 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1600 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1602 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1655 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
    "std::ostream::operator&lt;&lt;(int)", referenced from:
        l1348 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1481 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1482 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1483 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1585 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1600 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        l1602 in libscanditsdk-iphone-2.2.5.a(mirasense.o)
        ...
  ld: symbol(s) not found for architecture armv7
  clang: error: linker command failed with exit code 1 (use -v to see invocation)
  </code></pre>
  
  <p>Maybe something with armv7. How do i set this correctly. Works fine on the simulator</p>