#487: print less useless info during builds ------------------------------+--------------------------------------------- Reporter: duncan | Owner: Type: enhancement | Status: new Priority: normal | Milestone: Component: Cabal library | Version: 1.6.0.1 Severity: minor | Keywords: Difficulty: easy (<4 hours) | Ghcversion: Platform: | ------------------------------+--------------------------------------------- Here's an example from a blog post: {{{ $ cabal update $ cabal install gofer-prelude Resolving dependencies... Downloading gofer-prelude-2.30... Configuring gofer-prelude-2.30... Preprocessing library gofer-prelude-2.30... Building gofer-prelude-2.30... [1 of 1] Compiling Prelude.Gofer ( Prelude/Gofer.hs, dist/build/Prelude/Gofer.o ) /usr/bin/ar: creating dist/build/libHSgofer-prelude-2.30.a Installing library in /home/dons/.cabal/lib/gofer-prelude-2.30/ghc-6.10.1 Registering gofer-prelude-2.30... Reading package info from "dist/installed-pkg-config" ... done. Writing new package config file... done. }}} Which bits are useful and useless? I mean at the standard verbosity level. I bet this is useless: {{{ Preprocessing library gofer-prelude-2.30... }}} Does it actually do any pre-processing? See also #475. Useless: {{{ /usr/bin/ar: creating dist/build/libHSgofer-prelude-2.30.a }}} This is produced by the `ar` program. We can however pass it a flag to tell it to be quiet. Not especially useful: {{{ Installing library in /home/dons/.cabal/lib/gofer-prelude-2.30/ghc-6.10.1 }}} This message is generated by Cabal. At the default verbosity level we probably only need something like "Installing gofer-prelude-2.30..." Useless: {{{ Reading package info from "dist/installed-pkg-config" ... done. Writing new package config file... done. }}} This message is generated by ghc-pkg. We should patch ghc-pkg to not be so verbose by default. That message is only needed at a higher verbosity level. So if we get all these things fixed it'd look like: {{{ $ cabal update Downloading package list from hackage.haskell.org $ cabal install gofer-prelude Resolving dependencies... Downloading gofer-prelude-2.30... Configuring gofer-prelude-2.30... Building gofer-prelude-2.30... [1 of 1] Compiling Prelude.Gofer ( Prelude/Gofer.hs, dist/build/Prelude/Gofer.o ) Installing gofer-prelude-2.30... Registering gofer-prelude-2.30... }}} This is assuming the package in question doesn't actually need any pre- processing. Even the pre-processing message could be elided if we don't think it'll take that long. I wonder if we can get ghc to not tell us the source and object file locations. While it is sometimes useful while hacking, for batch builds we do not need it. -- Ticket URL: http://hackage.haskell.org/trac/hackage/ticket/487 Hackage http://haskell.org/cabal/ Hackage: Cabal and related projects