ninja: pip install ninja failed when pip>=10.0.0

Seems this is known problem about pip>=10.0.0 https://stackoverflow.com/a/49867265

pip install ninja
Collecting ninja
  Using cached https://files.pythonhosted.org/packages/9c/51/332390f0e25882b8e1744ef626af70c780df66e2ba07c45428ad091be739/ninja-1.8.2.tar.gz
    Complete output from command python setup.py egg_info:
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/private/var/folders/fg/mc37_2nx4sl19cv74vk3m3p80000gp/T/pip-install-1i0m4nnd/ninja/setup.py", line 6, in <module>
        from pip.req import parse_requirements
    ModuleNotFoundError: No module named 'pip.req'

Updated: Even I downgrade to 9.0.3, it still failed.

  An error occurred while configuring with CMake.
    Command:
      "cmake" "/private/var/folders/fg/mc37_2nx4sl19cv74vk3m3p80000gp/T/pip-build-qbb7u8b5/ninja" "-G" "Unix Makefiles" "-DCMAKE_INSTALL_PREFIX:PATH=/private/var/folders/fg/mc37_2nx4sl19cv74vk3m3p80000gp/T/pip-build-qbb7u8b5/ninja/_skbuild/cmake-install" "-DPYTHON_EXECUTABLE:FILEPATH=/Users/wenhao/.virtualenvs/ml_3.6/bin/python3.6" "-DPYTHON_VERSION_STRING:STRING=3.6.5" "-DPYTHON_INCLUDE_DIR:PATH=/usr/local/var/pyenv/versions/3.6.5/include/python3.6m" "-DPYTHON_LIBRARY:FILEPATH=/usr/local/var/pyenv/versions/3.6.5/lib/libpython3.6m.a" "-DSKBUILD:BOOL=TRUE" "-DCMAKE_MODULE_PATH:PATH=/Users/wenhao/.virtualenvs/ml_3.6/lib/python3.6/site-packages/skbuild/resources/cmake" "-DCMAKE_BUILD_TYPE:STRING=Release"
    Source directory:
      /private/var/folders/fg/mc37_2nx4sl19cv74vk3m3p80000gp/T/pip-build-qbb7u8b5/ninja
    Working directory:
      /private/var/folders/fg/mc37_2nx4sl19cv74vk3m3p80000gp/T/pip-build-qbb7u8b5/ninja/_skbuild/cmake-build
  Please see CMake's output for more information.

  ----------------------------------------
  Failed building wheel for ninja