/usr/lib/python2.7/distutils/extension.py:133: UserWarning: Unknown Extension options: 'optional'
  warnings.warn(msg)
running build
running build_py
creating build
creating build/lib.linux-x86_64-2.7
copying scandir.py -> build/lib.linux-x86_64-2.7
running build_ext
building '_scandir' extension
creating build/temp.linux-x86_64-2.7
gcc -pthread -fno-strict-aliasing -march=x86-64 -mtune=generic -O2 -pipe -fno-plt -DNDEBUG -march=x86-64 -mtune=generic -O2 -pipe -fno-plt -march=x86-64 -mtune=generic -O2 -pipe -fno-plt -fexceptions -Wp,-D_FORTIFY_SOURCE=2 -Wformat -Werror=format-security -fstack-clash-protection -fcf-protection -flto=auto -fPIC -I/usr/include/python2.7 -c _scandir.c -o build/temp.linux-x86_64-2.7/_scandir.o
gcc -pthread -shared -Wl,-O1,--sort-common,--as-needed,-z,relro,-z,now -Wl,-O1,--sort-common,--as-needed,-z,relro,-z,now -flto=auto -march=x86-64 -mtune=generic -O2 -pipe -fno-plt -fexceptions -Wp,-D_FORTIFY_SOURCE=2 -Wformat -Werror=format-security -fstack-clash-protection -fcf-protection -flto=auto build/temp.linux-x86_64-2.7/_scandir.o -L/usr/lib -lpython2.7 -o build/lib.linux-x86_64-2.7/_scandir.so