freeze ghc to version 7.10.2, fixes #225

[kikofernandez]

freeze ghc to version 7.10.2.

[albertnetymk]

Freezing might be a bit overreacting. The root cause of this incident is that ghc version on CI differs from the versions used in some dev machines.

[kikofernandez]

it's not related to ghc only. I believe it's better to know that we are breaking something on purpose and relying on CI rather than trusting everything on the CI

[albertnetymk]

it's not related to ghc only

Then, I misunderstood the problem. I thought the problem is that CI uses ghc 7.10, but in some dev boxes, 7.8 is used. What's the rest of the problem other than ghc version?

[kikofernandez]

no... I believe CI uses 7.8 or something... it's been ages since last time I had to update anything there. @albertnetymk could you post your preliminaries? you are the only one using Linux

[albertnetymk]

What do you mean by preliminaries? My env:

$ ghc --version
The Glorious Glasgow Haskell Compilation System, version 7.10.1
$ cabal --version
cabal-install version 1.22.2.0
using version 1.22.2.0 of the Cabal library

[kikofernandez]

what about g++ version or clang?

[albertnetymk]

My clang might be a bit too new.

Ubuntu clang version 3.6.1-svn237433-1~exp1 (branches/release_36) (based on LLVM 3.6.1)
gcc (Ubuntu 4.8.2-19ubuntu1) 4.8.2
premake4 (Premake Build Script Generator) 4.3

[EliasC]

I like this. I'll merge it if no one objects.

[albertnetymk]

While we are on this, why is word preliminary used, instead of dependency?

[EliasC]

@albertnetymk In this context I think the terms could be used interchangeably. The preliminaries are what you need to install first, before installing anything else. The dependencies are the pieces of software needed for the compiler to build (and thus, you need to install them first).