Building, changes to config not saving

Oh, so close. Finally got the env with only the packages that I want but it's still failing. So close now!

 make[2] package/install
 make[2] target/install
 make[3] -C target/linux install
make -r world: build failed. Please re-run make with -j1 V=s or V=sc for a higher verbosity level to see what's going on
/clients/openwrt-18.06/include/toplevel.mk:216: recipe for target 'world' failed
make: *** [world] Error 1

There's a script to back up the config file, which is useful for version control...

Hi, sorry for the long delay, I work on this as I can.
As mentioned, I finally have the build I need now. The only problem left is that it is not using the custom files in the files/ directory that I included.

Do I need to tell the environment about the files/ directory so that it will use my custom network file for example or should it just automatically use it once its there?
I have for example
files/etc/config/network to change the static IP to DHCP. The build completes but it's not using my custom file.

cat build_dir/target-mipsel_24kc_musl/root-ramips/etc/config/network
contains the default network rather than mine.