[Nix-dev] Reducing the number of Haskell builds in the NixOS/Nixpkgs channel

[Lluís Batlle i Rossell]

On Wed, Jan 30, 2013 at 02:23:28PM +0100, Andres Loeh wrote:
> >>   haskellPackages_ghc6104             = recurseIntoAttrs (haskell.packages_ghc6104);
> >>   haskellPackages_ghc6123             = recurseIntoAttrs (haskell.packages_ghc6123);
> >>   haskellPackages_ghc704              = recurseIntoAttrs (haskell.packages_ghc704);
> >>   haskellPackages_ghc741              = recurseIntoAttrs (haskell.packages_ghc741);
> >>   haskellPackages_ghc742_no_profiling = recurseIntoAttrs (haskell.packages_ghc741.noProfiling);
> >>   haskellPackages_ghc742_profiling    = recurseIntoAttrs (haskell.packages_ghc741.profiling);
> >>   haskellPackages_ghc742              = recurseIntoAttrs (haskell.packages_ghc742.highPrio);
> >>   haskellPackages_ghc761              = recurseIntoAttrs (haskell.packages_ghc761);
> >>   haskellPackages_ghc762              = recurseIntoAttrs (haskell.packages_ghc762);
> >
> > This number of builds is not really a problem for Hydra, but it is for the
> > binary channel generation: the NixOS and Nixpkgs channels are only updated after
> > *every* package in the latest jobset evaluation has been built and mirrored.  So
> > having 71% of the channel consist of Haskell packages adds considerable latency.
> >
> > I would suggest removing most of the GHC versions from the channels (i.e. remove
> > "recurseIntoAttrs"), except the default (7.4.2) and the latest (7.6.2).  If
> > desired, we could create a separate Hydra jobset to build the other versions.
> 
> At the moment, this would be fine. I'm hardly using anything that's
> older than 7.4.2 right now. There are phases in GHC development though
> where having builds for three different versions is really helpful.
> 
> Creating a separate Hydra jobset might be a good option, but I have no
> experience with how that's done.

Hello,

yes, I think it would be nice, if nixpkgs/trunk were free of the haskellPackages
clutter, specially in the job list / status overview. Hydra does on-browser
folding in some places, like logs; maybe adding folding to the statusOverview /
job list would be good, instead.