On Wed, Feb 17, 2016 at 2:58 AM, Ben Gamari <b...@smart-cactus.org> wrote: > Yes, it would be great if someone could step up to look at Cabal's > performance. Running `cabal build` on an up-to-date tree of a > moderately-sized (10 kLoC, 8 components, 60 modules) Haskell project I > have laying around takes over 5 seconds from start-to-finish. > > `cabal build`ing just a single executable component takes 4 seconds. > This same executable takes 48 seconds for GHC to build from scratch with > optimization and 12 seconds without.
I have contributed several performance patches to Cabal in the past, so I feel somewhat qualified to speak here. The remaining slowness in `cabal build` is mostly due to the pre-process phase. There work in progress which may improve this situation. We could also look at separating the pre-process phase from the build phase. (It seems odd to call it `pre-process` when it is *always* run during the build phase, doesn't it?) This has the advantage of sidestepping the slowness issue entirely, but it may break some users' workflows. Is that trade-off worth it? We could use user feedback here. Regards, Tom _______________________________________________ ghc-devs mailing list ghc-devs@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs
