c++ - 'wchar.h' file not found

Question

I know about this question: macOS 'wchar.h' File Not Found 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?

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 <wchar.h>
              ^~~~~~~~~
1 error generated.
make: *** [build/src/app.cpp.o] Error 1

since wchar.h exists both in the xcode app, and in the /Library/Developer/CommandLineTools I think that it looks for it in some completely unrelated folder.

Answer 1

I had the same problem after upgrading to macOS High Sierra. A project which was compiling before stopped working with this error. In my case, the project files had been generated by the CMake application. The solution was to run CMake, 'Delete Cache', and 'Configure' the project again. This corrected the sysroot directory reference in the make files to point to the new SDK and the error was resolved.