>>> host-python-networkx 2.4 Extracting
gzip -d -c /tmp/instance-0/dl/python-networkx/networkx-2.4.tar.gz | /tmp/instance-0/output-1/host/bin/tar --strip-components=1 -C /tmp/instance-0/output-1/build/host-python-networkx-2.4   -xf -
>>> host-python-networkx 2.4 Patching
>>> host-python-networkx 2.4 Configuring
>>> host-python-networkx 2.4 Building
(cd /tmp/instance-0/output-1/build/host-python-networkx-2.4//; PATH="/tmp/instance-0/output-1/host/bin:/tmp/instance-0/output-1/host/sbin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin" PYTHONNOUSERSITE=1 PATH="/tmp/instance-0/output-1/host/bin:/tmp/instance-0/output-1/host/sbin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin" PKG_CONFIG="/tmp/instance-0/output-1/host/bin/pkg-config" PKG_CONFIG_SYSROOT_DIR="/" PKG_CONFIG_ALLOW_SYSTEM_CFLAGS=1 PKG_CONFIG_ALLOW_SYSTEM_LIBS=1 PKG_CONFIG_LIBDIR="/tmp/instance-0/output-1/host/lib/pkgconfig:/tmp/instance-0/output-1/host/share/pkgconfig" AR="/usr/bin/ar" AS="/usr/bin/as" LD="/usr/bin/ld" NM="/usr/bin/nm" CC="/usr/bin/gcc" GCC="/usr/bin/gcc" CXX="/usr/bin/g++" CPP="/usr/bin/cpp" OBJCOPY="/usr/bin/objcopy" RANLIB="/usr/bin/ranlib" CPPFLAGS="-I/tmp/instance-0/output-1/host/include" CFLAGS="-O2 -I/tmp/instance-0/output-1/host/include" CXXFLAGS="-O2 -I/tmp/instance-0/output-1/host/include" LDFLAGS="-L/tmp/instance-0/output-1/host/lib -Wl,-rpath,/tmp/instance-0/output-1/host/lib" INTLTOOL_PERL=/usr/bin/perl  /tmp/instance-0/output-1/host/bin/python setup.py build  )
NetworkX 2.3+ requires Python 3.5 or later (2.7 detected).
             
For Python 2.7, please install version 2.2 using:

$ pip install 'networkx==2.2'

make: *** [package/pkg-generic.mk:269: /tmp/instance-0/output-1/build/host-python-networkx-2.4/.stamp_built] Error 1
make: Leaving directory '/tmp/instance-0/buildroot'