This is one of the compilation errors when executing ./setup.sh in lua-trafficgen repo:

/root/lua-trafficgen/MoonGen/libmoon/deps/dpdk/lib/librte_eal/linuxapp/eal/eal_memory.c:1710:3: error: 'size' may be used uninitialized in this function [-Werror=maybe-uninitialized]
   munmap(hp, size);
   ^~~~~~~~~~~~~~~~

Looking at git log of /lua-trafficgen/MoonGen/  it seems that the last commit is from 2016
commit 38d70bbfd457705f334d14089d0338fcdb3c369d (HEAD)
Author: Paul Emmerich <[email protected]>
Date:   Wed Nov 2 14:16:03 2016 +0100

    move software rate control from libmoon to moongen



This is the patch that fixes that bug: http://dpdk.org/dev/patchwork/patch/15922/

Looking at MoonGen repo and running the build.sh command, dpdk includes a recent version of eal_memory.c where the line
    off_t size = 0;
is included.