Does not build with ghc 8

[idontgetoutmuch]

cabal: Could not resolve dependencies:
trying: diagrams-haddock-0.3.0.10 (user goal)
next goal: base (dependency of diagrams-haddock-0.3.0.10)
rejecting: base-4.9.0.0/installed-4.9... (conflict: diagrams-haddock =>
base>=4.4 && <4.9)
rejecting: base-4.9.0.0, base-4.8.2.0, base-4.8.1.0, base-4.8.0.0,
base-4.7.0.2, base-4.7.0.1, base-4.7.0.0, base-4.6.0.1, base-4.6.0.0,
base-4.5.1.0, base-4.5.0.0, base-4.4.1.0, base-4.4.0.0, base-4.3.1.0,
base-4.3.0.0, base-4.2.0.2, base-4.2.0.1, base-4.2.0.0, base-4.1.0.0,
base-4.0.0.0, base-3.0.3.2, base-3.0.3.1 (constraint from non-upgradeable
package requires installed instance)
Dependency tree exhaustively searched.

[byorgey]

Thanks for the report. We are aware of the need to upgrade everything for GHC 8. For a while we were waiting for upstream packages to update. I'm now working on getting all the diagrams pacakges updated. Nothing difficult, just lots of fiddly things to change.

[idontgetoutmuch]

Hi Brent, Any news on this? I'd like to use it for the Kalman filter package I am working on.

[byorgey]

I guess the news is that @cchalmers just fixed it? =) Well, in git at least. diagrams-builder and diagrams-haddock have been giving me trouble. I'll have to look at making new point releases of them next.

[cchalmers]

Yeah, it works for me but Travis seems to give a different build error for each version. (I don't know what to make of https://travis-ci.org/diagrams/diagrams-haddock/jobs/154830965). Maybe it would be easier drop older ghc support for this and builder?

[byorgey]

Actually that travis error is straightforward to decipher if you scroll all the way to the bottom: haskell-src-exts-simple requires base >= 4.7. So yeah, I think dropping support for older GHCs is the way to go. Honestly I don't even know why we are still testing diagrams-haddock on GHC 7.6.