docs: def build_extension(self, ext):
          """build_extension.
  
          :raises BuildFailed: cythonize impossible
          """
          try:
              build_ext.build_ext.build_extension(self, ext)
          except (
              distutils.errors.CCompilerError,
              distutils.errors.DistutilsExecError,
              distutils.errors.DistutilsPlatformError,
              ValueError,
          ):
              raise BuildFailed()