#89: Sharing of object files between executable builds? ------------------------------------+--------------------------------------- Reporter: bjorn@bringert.net | Owner: Type: enhancement | Status: new Priority: low | Milestone: Component: Cabal library | Version: Severity: minor | Resolution: Keywords: jgoerzen@complete.org | Difficulty: normal Ghcversion: 6.4.2 | Platform: Linux ------------------------------------+--------------------------------------- Comment (by guest): I'd mention that this lack of sharing between sections has bitten me recently (as in an error and not an inefficiency sense) while I was updating Greencard. So the Greencard package provides two main things; it provides a src/ which contains all sorts of modules which gets compiled down to the executable 'greencard-bin', and it provides a library, Foreign.Greencard, which naturally requires Greencard to be compiled. The makefile accomplishes this by building greencard-bin in place in src/, and then running something like ../src/greencard-bin on the lib/ files. Everything comes out hunky-dory. But when put into Cabal format, it needs to be split between Executable and Library sections. So, suppose someone goes to install a Cabalized greencard. (This means no greencard is installed.) Cabal begins the configuration. It detects that no greencard is accessible - 'No greencard found'. It's otherwise happy, and it begins chasing down the files. Everything in 'Executable greencard'? Good. .lhs and .hs files, no sweat. Everything in 'Library'? Uh oh! This 'lib/Foreign/GreenCard.gc', it requires 'greencard'! And the build barfs. Which is silly, since it could and would be able to build the greencard necessary for the library! I think I'm going to have split greencard up, and have a greencard and greencard-lib, making greencard-lib depend on greencard. This was the solution I used the last time I encountered a problem like this... -- gwern -- Ticket URL: http://hackage.haskell.org/trac/hackage/ticket/89#comment:4 Hackage http://haskell.org/cabal/ Hackage: Cabal and related projects