[Help Needed] - Debugging compilation time

[Hipreme]

Hey guys, I have been complaining a lot of time right now from D 
compilation speed at least for my project.

I have:
- Underused CTFE
- Underused Templates
- Avoided importing standard libraries
- Created a multi module projects for better code reuse

Those are all the techniques I have tried to maintain my 
compilation times lower, yet, It still builds slow even when 
using the --combined (which does a single compiler run on dub)

So, doesn't matter if all is imported at once or not, it seems 
the problem seems to be somewhere in my project which I've been 
unable to find. I wanted to show someone who is more experienced 
on the time trace from LDC to check what I've been doing wrong.

This time trace took 9 seconds. DMD takes 7 seconds to build my 
project. Adam has built his entire arsd in 2.5 seconds, while my 
PC is faster and arsd is much bigger than my project, this does 
not make any sense. So I would gladly wish you guys help:

My repository: https://github.com/MrcSnm/HipremeEngine/
My time trace: https://ufile.io/gmvw1wlu (This time trace will be 
in air for 30 days only)