You're cross compiling, so you need to have the cross libraries installed. Did you also
sudo dpkg --add-architecture armhf
sudo apt update
sudo apt install libmnl-dev:armhf
I can't reproduce here at all:
┌──(steev㉿panda)-[/storage/cross/libnftnl]
└─$ ionice -c 3 nice -n19 make -j$((nproc -2))
make all-recursive
make[1]: Entering directory '/storage/cross/libnftnl'
Making all in src
make[2]: Entering directory '/storage/cross/libnftnl/src'
CC utils.lo
CC batch.lo
CC flowtable.lo
CC common.lo
CC gen.lo
CC table.lo
CC trace.lo
CC chain.lo
CC object.lo
CC rule.lo
CC set.lo
CC set_elem.lo
CC ruleset.lo
CC udata.lo
CC expr.lo
CC expr_ops.lo
CC expr/bitwise.lo
CC expr/byteorder.lo
CC expr/cmp.lo
CC expr/range.lo
CC expr/connlimit.lo
CC expr/counter.lo
CC expr/ct.lo
CC expr/data_reg.lo
CC expr/dup.lo
CC expr/exthdr.lo
CC expr/flow_offload.lo
CC expr/fib.lo
CC expr/fwd.lo
CC expr/limit.lo
CC expr/log.lo
CC expr/lookup.lo
CC expr/dynset.lo
CC expr/immediate.lo
CC expr/match.lo
CC expr/meta.lo
CC expr/numgen.lo
CC expr/nat.lo
CC expr/tproxy.lo
CC expr/objref.lo
CC expr/payload.lo
CC expr/queue.lo
CC expr/quota.lo
CC expr/reject.lo
CC expr/rt.lo
CC expr/target.lo
CC expr/tunnel.lo
CC expr/masq.lo
CC expr/redir.lo
CC expr/hash.lo
CC expr/socket.lo
CC expr/synproxy.lo
CC expr/osf.lo
CC expr/xfrm.lo
CC obj/counter.lo
CC obj/ct_helper.lo
CC obj/quota.lo
CC obj/tunnel.lo
CC obj/limit.lo
CC obj/synproxy.lo
CC obj/ct_timeout.lo
CC obj/secmark.lo
CC obj/ct_expect.lo
CCLD libnftnl.la
make[2]: Leaving directory '/storage/cross/libnftnl/src'
Making all in include
make[2]: Entering directory '/storage/cross/libnftnl/include'
Making all in libnftnl
make[3]: Entering directory '/storage/cross/libnftnl/include/libnftnl'
make[3]: Nothing to be done for 'all'.
make[3]: Leaving directory '/storage/cross/libnftnl/include/libnftnl'
Making all in linux
make[3]: Entering directory '/storage/cross/libnftnl/include/linux'
Making all in netfilter
make[4]: Entering directory '/storage/cross/libnftnl/include/linux/netfilter'
make[4]: Nothing to be done for 'all'.
make[4]: Leaving directory '/storage/cross/libnftnl/include/linux/netfilter'
make[4]: Entering directory '/storage/cross/libnftnl/include/linux'
make[4]: Nothing to be done for 'all-am'.
make[4]: Leaving directory '/storage/cross/libnftnl/include/linux'
make[3]: Leaving directory '/storage/cross/libnftnl/include/linux'
make[3]: Entering directory '/storage/cross/libnftnl/include'
make[3]: Nothing to be done for 'all-am'.
make[3]: Leaving directory '/storage/cross/libnftnl/include'
make[2]: Leaving directory '/storage/cross/libnftnl/include'
Making all in examples
make[2]: Entering directory '/storage/cross/libnftnl/examples'
make[2]: Nothing to be done for 'all'.
make[2]: Leaving directory '/storage/cross/libnftnl/examples'
Making all in tests
make[2]: Entering directory '/storage/cross/libnftnl/tests'
make[2]: Nothing to be done for 'all'.
make[2]: Leaving directory '/storage/cross/libnftnl/tests'
make[2]: Entering directory '/storage/cross/libnftnl'
make[2]: Leaving directory '/storage/cross/libnftnl'
make[1]: Leaving directory '/storage/cross/libnftnl' |