title: Installation of dlib with pip fails on Windows 10
body: <p>I tried a lot to install <code>pip install dlib</code> but it always shows an error and I reinstalled <code>cmake</code>.</p>
  
  <p>I got the error:</p>
  
  <pre><code>pip install dlib
  Collecting dlib
    Using cached https://files.pythonhosted.org/packages/1e/62/aacb236d21fbd08148b1d517d58a9d80ea31bdcd386d26f21f8b23b1eb28/dlib-19.18.0.tar.gz
  Building wheels for collected packages: dlib
    Building wheel for dlib (setup.py) ... error
    ERROR: Command errored out with exit status 1:
     command: 'c:\program files\python37\python.exe' -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'C:\\Users\\hp\\AppData\\Local\\Temp\\pip-install-yynf7mue\\dlib\\setup.py'"'"'; __file__='"'"'C:\\Users\\hp\\AppData\\Local\\Temp\\pip-install-yynf7mue\\dlib\\setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' bdist_wheel -d 'C:\Users\hp\AppData\Local\Temp\pip-wheel-0eyy_3vd' --python-tag cp37
         cwd: C:\Users\hp\AppData\Local\Temp\pip-install-yynf7mue\dlib\
    Complete output (55 lines):
    running bdist_wheel
    running build
    running build_py
    package init file 'dlib\__init__.py' not found (or not a regular file)
    running build_ext
    Building extension for Python 3.7.4 (tags/v3.7.4:e09359112e, Jul  8 2019, 20:34:20) [MSC v.1916 64 bit (AMD64)]
    Invoking CMake setup: 'cmake C:\Users\hp\AppData\Local\Temp\pip-install-yynf7mue\dlib\tools\python -DCMAKE_LIBRARY_OUTPUT_DIRECTORY=C:\Users\hp\AppData\Local\Temp\pip-install-yynf7mue\dlib\build\lib.win-amd64-3.7 -DPYTHON_EXECUTABLE=c:\program files\python37\python.exe -DCMAKE_LIBRARY_OUTPUT_DIRECTORY_RELEASE=C:\Users\hp\AppData\Local\Temp\pip-install-yynf7mue\dlib\build\lib.win-amd64-3.7 -A x64'
    -- Building for: NMake Makefiles
    CMake Error at CMakeLists.txt:3 (project):
      Generator
  
        NMake Makefiles
  
      does not support platform specification, but platform
  
        x64
  
      was specified.
  
  
    CMake Error: CMAKE_C_COMPILER not set, after EnableLanguage
    CMake Error: CMAKE_CXX_COMPILER not set, after EnableLanguage
    -- Configuring incomplete, errors occurred!
    See also "C:/Users/hp/AppData/Local/Temp/pip-install-yynf7mue/dlib/build/temp.win-amd64-3.7/Release/CMakeFiles/CMakeOutput.log".
    Traceback (most recent call last):
      File "&lt;string&gt;", line 1, in &lt;module&gt;
      File "C:\Users\hp\AppData\Local\Temp\pip-install-yynf7mue\dlib\setup.py", line 261, in &lt;module&gt;
        'Topic :: Software Development',
      File "c:\program files\python37\lib\site-packages\setuptools\__init__.py", line 145, in setup
        return distutils.core.setup(**attrs)
      File "c:\program files\python37\lib\distutils\core.py", line 148, in setup
        dist.run_commands()
      File "c:\program files\python37\lib\distutils\dist.py", line 966, in run_commands
        self.run_command(cmd)
      File "c:\program files\python37\lib\distutils\dist.py", line 985, in run_command
        cmd_obj.run()
      File "c:\program files\python37\lib\site-packages\wheel\bdist_wheel.py", line 192, in run
        self.run_command('build')
      File "c:\program files\python37\lib\distutils\cmd.py", line 313, in run_command
        self.distribution.run_command(command)
      File "c:\program files\python37\lib\distutils\dist.py", line 985, in run_command
        cmd_obj.run()
      File "c:\program files\python37\lib\distutils\command\build.py", line 135, in run
        self.run_command(cmd_name)
      File "c:\program files\python37\lib\distutils\cmd.py", line 313, in run_command
        self.distribution.run_command(command)
      File "c:\program files\python37\lib\distutils\dist.py", line 985, in run_command
        cmd_obj.run()
      File "C:\Users\hp\AppData\Local\Temp\pip-install-yynf7mue\dlib\setup.py", line 135, in run
        self.build_extension(ext)
      File "C:\Users\hp\AppData\Local\Temp\pip-install-yynf7mue\dlib\setup.py", line 172, in build_extension
        subprocess.check_call(cmake_setup, cwd=build_folder)
      File "c:\program files\python37\lib\subprocess.py", line 347, in check_call
        raise CalledProcessError(retcode, cmd)
    subprocess.CalledProcessError: Command '['cmake', 'C:\\Users\\hp\\AppData\\Local\\Temp\\pip-install-yynf7mue\\dlib\\tools\\python', '-DCMAKE_LIBRARY_OUTPUT_DIRECTORY=C:\\Users\\hp\\AppData\\Local\\Temp\\pip-install-yynf7mue\\dlib\\build\\lib.win-amd64-3.7', '-DPYTHON_EXECUTABLE=c:\\program files\\python37\\python.exe', '-DCMAKE_LIBRARY_OUTPUT_DIRECTORY_RELEASE=C:\\Users\\hp\\AppData\\Local\\Temp\\pip-install-yynf7mue\\dlib\\build\\lib.win-amd64-3.7', '-A', 'x64']' returned non-zero exit status 1.
    ----------------------------------------
    ERROR: Failed building wheel for dlib
    Running setup.py clean for dlib
  Failed to build dlib
  Installing collected packages: dlib
      Running setup.py install for dlib ... error
      ERROR: Command errored out with exit status 1:
       command: 'c:\program files\python37\python.exe' -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'C:\\Users\\hp\\AppData\\Local\\Temp\\pip-install-yynf7mue\\dlib\\setup.py'"'"'; __file__='"'"'C:\\Users\\hp\\AppData\\Local\\Temp\\pip-install-yynf7mue\\dlib\\setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record 'C:\Users\hp\AppData\Local\Temp\pip-record-qzmuuf53\install-record.txt' --single-version-externally-managed --compile
           cwd: C:\Users\hp\AppData\Local\Temp\pip-install-yynf7mue\dlib\
      Complete output (57 lines):
      running install
      running build
      running build_py
      package init file 'dlib\__init__.py' not found (or not a regular file)
      running build_ext
      Building extension for Python 3.7.4 (tags/v3.7.4:e09359112e, Jul  8 2019, 20:34:20) [MSC v.1916 64 bit (AMD64)]
      Invoking CMake setup: 'cmake C:\Users\hp\AppData\Local\Temp\pip-install-yynf7mue\dlib\tools\python -DCMAKE_LIBRARY_OUTPUT_DIRECTORY=C:\Users\hp\AppData\Local\Temp\pip-install-yynf7mue\dlib\build\lib.win-amd64-3.7 -DPYTHON_EXECUTABLE=c:\program files\python37\python.exe -DCMAKE_LIBRARY_OUTPUT_DIRECTORY_RELEASE=C:\Users\hp\AppData\Local\Temp\pip-install-yynf7mue\dlib\build\lib.win-amd64-3.7 -A x64'
      -- Building for: NMake Makefiles
      CMake Error at CMakeLists.txt:3 (project):
        Generator
  
          NMake Makefiles
  
        does not support platform specification, but platform
  
          x64
  
        was specified.
  
  
      CMake Error: CMAKE_C_COMPILER not set, after EnableLanguage
      CMake Error: CMAKE_CXX_COMPILER not set, after EnableLanguage
      -- Configuring incomplete, errors occurred!
      See also "C:/Users/hp/AppData/Local/Temp/pip-install-yynf7mue/dlib/build/temp.win-amd64-3.7/Release/CMakeFiles/CMakeOutput.log".
      Traceback (most recent call last):
        File "&lt;string&gt;", line 1, in &lt;module&gt;
        File "C:\Users\hp\AppData\Local\Temp\pip-install-yynf7mue\dlib\setup.py", line 261, in &lt;module&gt;
          'Topic :: Software Development',
        File "c:\program files\python37\lib\site-packages\setuptools\__init__.py", line 145, in setup
          return distutils.core.setup(**attrs)
        File "c:\program files\python37\lib\distutils\core.py", line 148, in setup
          dist.run_commands()
        File "c:\program files\python37\lib\distutils\dist.py", line 966, in run_commands
          self.run_command(cmd)
        File "c:\program files\python37\lib\distutils\dist.py", line 985, in run_command
          cmd_obj.run()
        File "c:\program files\python37\lib\site-packages\setuptools\command\install.py", line 61, in run
          return orig.install.run(self)
        File "c:\program files\python37\lib\distutils\command\install.py", line 545, in run
          self.run_command('build')
        File "c:\program files\python37\lib\distutils\cmd.py", line 313, in run_command
          self.distribution.run_command(command)
        File "c:\program files\python37\lib\distutils\dist.py", line 985, in run_command
          cmd_obj.run()
        File "c:\program files\python37\lib\distutils\command\build.py", line 135, in run
          self.run_command(cmd_name)
        File "c:\program files\python37\lib\distutils\cmd.py", line 313, in run_command
          self.distribution.run_command(command)
        File "c:\program files\python37\lib\distutils\dist.py", line 985, in run_command
          cmd_obj.run()
        File "C:\Users\hp\AppData\Local\Temp\pip-install-yynf7mue\dlib\setup.py", line 135, in run
          self.build_extension(ext)
        File "C:\Users\hp\AppData\Local\Temp\pip-install-yynf7mue\dlib\setup.py", line 172, in build_extension
          subprocess.check_call(cmake_setup, cwd=build_folder)
        File "c:\program files\python37\lib\subprocess.py", line 347, in check_call
          raise CalledProcessError(retcode, cmd)
      subprocess.CalledProcessError: Command '['cmake', 'C:\\Users\\hp\\AppData\\Local\\Temp\\pip-install-yynf7mue\\dlib\\tools\\python', '-DCMAKE_LIBRARY_OUTPUT_DIRECTORY=C:\\Users\\hp\\AppData\\Local\\Temp\\pip-install-yynf7mue\\dlib\\build\\lib.win-amd64-3.7', '-DPYTHON_EXECUTABLE=c:\\program files\\python37\\python.exe', '-DCMAKE_LIBRARY_OUTPUT_DIRECTORY_RELEASE=C:\\Users\\hp\\AppData\\Local\\Temp\\pip-install-yynf7mue\\dlib\\build\\lib.win-amd64-3.7', '-A', 'x64']' returned non-zero exit status 1.
      ----------------------------------------
  ERROR: Command errored out with exit status 1: 'c:\program files\python37\python.exe' -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'C:\\Users\\hp\\AppData\\Local\\Temp\\pip-install-yynf7mue\\dlib\\setup.py'"'"'; __file__='"'"'C:\\Users\\hp\\AppData\\Local\\Temp\\pip-install-yynf7mue\\dlib\\setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record 'C:\Users\hp\AppData\Local\Temp\pip-record-qzmuuf53\install-record.txt' --single-version-externally-managed --compile Check the logs for full command output.
  </code></pre>