Source build way smaller than pre-build?

I built NetHunter kernel and fs from https://github.com/offensive-securit...er/tree/master for my Nexus 7 2013 wifi LP v5 (Razor).

The result was two files, 1. the kernel, which installed and shows in my about phone.
2. was update-kali.zip

The update.zip I built was 46MB in size and the chroot doesn't work.

i used the ./androidmenu.sh to build and it did everything for me.

Could anyone help me figure out why my flashable file is way smaller(46MB) than the pre-built ones(800MB) available for download?
And where did I go wrong that broke chroot?


EDIT:
Probably found out what caused this.

My virtual disk was "mounted with noexec"

I found out I could change it by doing "mount -o remount,exec,dev /media/root/VirtualDisk2"
Where VirtualDisk2 was the virtual drive I had the repos cloned on and was trying to execute the sh to build.

In the nethunter-installer directory look at the readme file for build instructions. Nethunter already has a kernel built for the nexus 7, so no need to build a new one. Follow the directions for the build.py for your device and add the --rootfs full to the end. This will add the chroot to the build.
That is the difference for the file size, the chroot will add the 600 mb+ to your build.