building / configuring X correctly

[Christopher Barry]

Greetings,

I got a new video card (radeon r9 390) to replace my aging hd7850 and it
caused total system lockups in debian sid after just a few minutes in
Blender. I decided to try to compile X and friends from source to get
the latest of everything (using build.sh). I compiled and installed the
latest LLVM and glamor as well. I've used multiple sources of
information from the web, but I'm stymied at this point.

Bottom line: I get no hw acceleration, only two of my three monitors
are displaying, and it's not clear to me if I have radeonsi running
right or not or at all.

I'm hoping someone can spot something obviously wrong I'm doing. There's
a bunch of different log and system output data in the linked zipfile
that may prove useful in understanding what's not right. 

https://filetea.me/t1sY8IXSi6CTVivPu7e3oRTsw

The build log shows a bunch of attempts at getting mesa to compile, but
indeed it finally did. I'm not sure my options are correct though.

I was using the resume feature and the modfile feature as well as -c
(clean) in build.sh, but it does not clean prior to a rebuild oddly. I
looped there failing for quite a while, until I just manually cleaned
and it compiled. I'm working on a patch for that now.

Anyway, thanks for having a look. If more/different data is needed
please advise.

Cheers