RE: GHC 7.6 failes to build

| > > For vector and random the same questions apply, but since we simply
| have lagging git repos for them we can create a ghc-7.6 branch.  Did you
| deliberately not do that, Ian?
| >
| > I expect Ian didn't branch DPH because it's not his job to test it
| with the GHC RC and ship it as part of the GHC source tarball. I can do
| the release part, but if Ian branches DPH as well then it is effectively
| zero-overhead to his existing workflow, and we won't hit this breakage
| again (I think?).
| 
| Right, I didn't branch them as we don't use them in the stable branch.
| But I can make the branches for future stable branches if that's useful,
| no problem.

I'm not quite getting this.  For all three (random, vector, DPH), are they used at all in the 7.6 branch?  

* If not, that's fine, but we must advertise that 7.6 doesn't work with DPH.
  I think that's ok... 7.8 will come soon with DPH stuff.

* If so, we should surely test them in the 7.6 branch, and that means 
  tagging them, doesn't it?

Do we build 'vector' solely because of DPH?  I think so.  Is the same true of 'random'?

Simon