title: 'wchar.h' file not found
body: <p>I know about this question: <a href="https://stackoverflow.com/questions/26185978/macos-wchar-h-file-not-found">macOS &#39;wchar.h&#39; File Not Found</a>
  but it did not help me. I've tried reinstalling xcode, reinstalling command line tools, restarting the system. wchar.h file is in place, but the compiler does not manage to find it. What else could I try? Maybe it is sysroot related? Any way to fix that?</p>
  
  <pre><code>macbooks-MacBook-Pro:Rack euphorbium$ sudo make
  c++ -Iinclude -Idep/include -Idep/lib/libzip/include -DVERSION=dev -MMD -O3 -march=core2 -ffast-math -g -Wall -DARCH_MAC -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.7.sdk -mmacosx-version-min=10.7 -DAPPLE -stdlib=libc++ -std=c++11 -stdlib=libc++ -c -o build/src/app.cpp.o src/app.cpp
  clang: warning: no such sysroot directory: '/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.7.sdk' [-Wmissing-sysroot]
  In file included from src/app.cpp:1:
  In file included from include/app.hpp:2:
  In file included from /Library/Developer/CommandLineTools/usr/include/c++/v1/vector:265:
  In file included from /Library/Developer/CommandLineTools/usr/include/c++/v1/iosfwd:90:
  /Library/Developer/CommandLineTools/usr/include/c++/v1/wchar.h:119:15: fatal error: 
        'wchar.h' file not found
  #include_next &lt;wchar.h&gt;
                ^~~~~~~~~
  1 error generated.
  make: *** [build/src/app.cpp.o] Error 1
  </code></pre>
  
  <p>since wchar.h exists both in the xcode app, and in the <code>/Library/Developer/CommandLineTools</code> I think that it looks for it in some completely unrelated folder. </p>