Hi, I also have the same problem, and python-openstackclient don't resolve the problem.

  Found existing installation: netifaces 0.10.4
    Uninstalling netifaces-0.10.4:
      Successfully uninstalled netifaces-0.10.4
  Running setup.py install for netifaces ... error
    Complete output from command /opt/bin/python2.7 -u -c "import setuptools, tokenize;__file__='/share/CACHEDEV1_DATA/.qpkg/Entware-ng/tmp/pip-build-VEkXNJ/netifaces/setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" install --record /opt/tmp/pip-c267Az-record/install-record.txt --single-version-externally-managed --compile:
    running install
    running build
    running build_ext
    checking for getifaddrs...found.
    checking for getnameinfo...found.
    checking for IPv6 socket IOCTLs...not found.
    checking for optional header files...netash/ash.h netatalk/at.h netax25/ax25.h neteconet/ec.h netipx/ipx.h netpacket/packet.h linux/irda.h linux/atm.h linux/llc.h linux/tipc.h linux/dn.h.
    checking whether struct sockaddr has a length field...no.
    checking which sockaddr_xxx structs are defined...at ax25 in in6 ipx un ash ec ll atmpvc atmsvc dn irda llc.
    checking for routing socket support...no.
    checking for sysctl(CTL_NET...) support...no.
    checking for netlink support...yes.
    will use netlink to read routing table
    building 'netifaces' extension
    x86_64-openwrt-linux-gnu-gcc -fno-strict-aliasing -O2 -pipe -fomit-frame-pointer -fno-caller-saves -fhonour-copts -Wno-error=unused-but-set-variable -Wno-error=unused-result -DNDEBUG -fno-inline -DNDEBUG -O2 -pipe -fomit-frame-pointer -fno-caller-saves -fhonour-copts -Wno-error=unused-but-set-variable -Wno-error=unused-result -fPIC -DNETIFACES_VERSION=0.10.5 -DHAVE_GETIFADDRS=1 -DHAVE_GETNAMEINFO=1 -DHAVE_NETASH_ASH_H=1 -DHAVE_NETATALK_AT_H=1 -DHAVE_NETAX25_AX25_H=1 -DHAVE_NETECONET_EC_H=1 -DHAVE_NETIPX_IPX_H=1 -DHAVE_NETPACKET_PACKET_H=1 -DHAVE_LINUX_IRDA_H=1 -DHAVE_LINUX_ATM_H=1 -DHAVE_LINUX_LLC_H=1 -DHAVE_LINUX_TIPC_H=1 -DHAVE_LINUX_DN_H=1 -DHAVE_SOCKADDR_AT=1 -DHAVE_SOCKADDR_AX25=1 -DHAVE_SOCKADDR_IN=1 -DHAVE_SOCKADDR_IN6=1 -DHAVE_SOCKADDR_IPX=1 -DHAVE_SOCKADDR_UN=1 -DHAVE_SOCKADDR_ASH=1 -DHAVE_SOCKADDR_EC=1 -DHAVE_SOCKADDR_LL=1 -DHAVE_SOCKADDR_ATMPVC=1 -DHAVE_SOCKADDR_ATMSVC=1 -DHAVE_SOCKADDR_DN=1 -DHAVE_SOCKADDR_IRDA=1 -DHAVE_SOCKADDR_LLC=1 -DHAVE_PF_NETLINK=1 -I/opt/include/python2.7 -c netifaces.c -o build/temp.linux-x86_64-2.7/netifaces.o
    netifaces.c: In function 'gateways':
    netifaces.c:1704:22: error: 'RTNL_FAMILY_MAX' undeclared (first use in this function)
       int def_priorities[RTNL_FAMILY_MAX];
                          ^~~~~~~~~~~~~~~
    netifaces.c:1704:22: note: each undeclared identifier is reported only once for each function it appears in
    error: command 'x86_64-openwrt-linux-gnu-gcc' failed with exit status 1

    ----------------------------------------
  Rolling back uninstall of netifaces
Command "/opt/bin/python2.7 -u -c "import setuptools, tokenize;__file__='/share/CACHEDEV1_DATA/.qpkg/Entware-ng/tmp/pip-build-VEkXNJ/netifaces/setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" install --record /opt/tmp/pip-c267Az-record/install-record.txt --single-version-externally-managed --compile" failed with error code 1 in /share/CACHEDEV1_DATA/.qpkg/Entware-ng/tmp/pip-build-VEkXNJ/netifaces/