Trouble Compiling from Source: cannot open file... + failed to produce

I am trying to build UE4 from the latest master branch (4.18), my setup is as follows:

Windows 10 Pro x64 (FCU)

VS 2017 Community (Workloads: Native Game + Native Desktop + Managed Desktop + 8.1 SDK)

I run GenerateProjectFiles.bat -2017 successfuly but when I try to build the UE4 project I get this:

I searched but found no error like this, I can’t think of anything right now so any help is much appreciated.

So I rerun Setup.bat and removed -exclude VS2015 to download additional files, this time the build went further but to my greatest sorrow after a full 12+ hours of waiting I got this finally:

What am I doing wrong?! and why this site is so inactive, this all could have been avoided if Epic provided precompiled build links, instead I have to waste a whole day to download the binaries and another to build them and many others to wait for an answer on a dead site as to why the build failed!