Support for monoid-extras-0.3.0.0

[peti]

Hi,

I tried to package diagrams-core in NixOS, but failed because we have updated to monoid-extras 0.3.x already, which diagrams-core doesn't support:

Building diagrams-core-0.6.0.2...
Preprocessing library diagrams-core-0.6.0.2...

src/Diagrams/Core/Trace.hs:48:18:
    Could not find module `Data.Monoid.PosInf'
    Perhaps you meant Data.Monoid.Inf (from monoid-extras-0.3.0.0)
    Use -v to see a list of the files searched for.

Is there maybe a simple fix for this issue?

[byorgey]

The simplest fix is to not update to monoid-extras 0.3 yet! I released it for a colleague who needs the new functionality. But I am not aware of any other packages that depend on it yet other than the diagrams packages, so it should not make much of a difference whether 0.2 or 0.3 is provided in NixOS.

That said, the fix is relatively simple. But off the top of my head I am not sure how easy it will be to integrate into the 0.6 branch as a bug fix release. I was not planning to update diagrams to monoid-extras-0.3 until the 0.7 release of diagrams (which will not be for a few months most likely). But I will take a look.

[byorgey]

Fixed via @12d1ab65 . Will be in the 0.7 release which should be out in a few weeks.