Unable to build community edition

Hi,

 Unable to build Master checkout of IJ community eidtion (checked on Dec 3, 2017).

What I get are a ton of missing jars in the .m2 folder which I understand is created by the internal Maven. Doesn't seem to be any way to fix this,  fix offers only to delete the dependency. 

If I click EDIT, I get a popup that says:

"Maven : *missing library name" Loading available versions..." 

which just hangs and gives no sign of life or indication that anything is actually happening. 

Manually looking for the indicated jars online and downloading them just leads to versioning and naming confusions of this sort-

Was missing assertJ. Found it online. Downloaded it. Unzipped it into .m2.repository.org and of course none of the names match with the path and can't be made to match since , I guess, the naming convention has changed or something ... 

Anyway, it seems like this can't be the intended procedure to build IJ. There are 30+ distinct TLDs  named in these error messages, each with their own versioning and naming issues summing to 87 errors involving maybe 60 or more distinct missing libraries / jars 

So what am I doing wrong here?

Screenshot of first X many\ errors provided.
.