Facing errors while building pfSense from its source code RELENG_2_7_1

[Mehroz Mustafa]

I am building pfSense from its source code, RELENG_2_7_1 for research and exploration purposes only, but I've been facing alot of issues while doing so.
I tried to follow an outdated guide and failed alot in my first two weeks, then I decided to look into the issues which some people were facing, and got a little help from it, now I'm stuck again more errors, here's the full detailed log file, I added some break points with the name "<======-Poyo *-======>" just to keep track of where I'm failing logs3.txt
After some trial and error, I found the lines which were causing the issues,

These two images show the main point where the error occurred (in case you don't wanna look at the several thousands of lines of log file) the make_world function inside /pfsense/tools/builder_common.conf is the root of all this.
And if you wanna check what changes I've made in the actual repositories then I'll post those links here as well.
Branch 2_7_1: I forked the whole git repo there, for diff version testing.
FreeBSD-ports
FreeBSD-src
pfsense

I'm nearly at my limits now since I've spent over 4 weeks on these errors.