tehgeekmeister’s blog

January 17, 2009

what to do when you can’t solve a problem with a hackage library you need?

Filed under: programming — Tags: — tehgeekmeister @ 8:12 pm

in trying to work on my graded reader project recently I encountered two problems that were beyond my ability to solve. the first was that HDBC’s quickQuery was loading all results into memory, while fetchAllRows was not loading any rows (in fact the query was never reaching postgresql). this made it so I couldn’t use HDBC with postgresql for my project. then I decided to try takusen, but couldn’t figure out the problems with the current cabal file for it, despite quite a lot of googling. I asked around on #haskell about both of these problems, and got some help, but neither got resolved; so my question for planet haskell is what should I do when I reach this sort of an impass? i’ll gladly fix any problems I can on my own and share the wealth, but I hate being stuck when it’s absolutely beyond me.


  1. Getting an answer from #haskell about specific problems like these requires a bit of luck, you need to find the right person online, in these cases you need a more persistent medium like haskell-cafe haskell.org .
    By the way this message is relevant to the takusen problem http://www.nabble.com/Re%3A-databases-in-Haskell—type-safety-p21263638.html
    And since i’ve fixed this same problem myself i’ve uploaded a patched tarball of takusen here http://code.haskell.org/~Saizan/Takusen- so you can at least try it out. It builds fine for me with ghc-6.10.1 and Cabal-, i’ve not uploaded it to hackage since i’m not the maintainer.
    The other option is to mail the maintainer directly.

    Comment by Andrea Vezzosi — January 17, 2009 @ 11:32 pm

  2. Contact the package maintainers. Their contact details are on the hackage pages. They’re all friendly helpful people who want their packages to work as well as possible.

    Make sure you send them as much detail as possible. Tell them what versions of software you are using (ghc, cabal etc) and what operating system and what database and version.

    Comment by Duncan — January 18, 2009 @ 6:27 am

  3. thanks both of you for your replies; I’ll give all of what you mentioned a try once I’m not relying on my iPhone for internet. for now I just wanted to make sure I didn’t forget about this before I got a chance to post about it later.

    Comment by tehgeekmeister — January 18, 2009 @ 8:23 am

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