[Haskell-cafe] Re: Haddock: Failed to create dependency graph (when adding sections with * or a module heading)

[Jared Updike]

Simple fix (terrible error message):

Move the ( up to the line with the module name. Previous bad code:

    module Data.DualMap
       -- * The @DualMap@ abstract type
       ( DualMap ()
       -- * (?) internal? -- exposed for testing purposes, for now...
       , dmFlip
       -- * converting to and from DualMap
       , toList, fromList, map
       -- * constructing a DualMap
       , empty, null, insert, union

Happy code looks like this:

    module Data.DualMap (
       -- * The @DualMap@ abstract type
         DualMap ()
       -- * (?) internal? -- exposed for testing purposes, for now...
       , dmFlip
       -- * converting to and from DualMap
       , toList, fromList, map
       -- * constructing a DualMap
       , empty, null, insert, union

Simple enough. I found this out by downloading DList [1] from hacakge
and gutting it and replacing the code with my own code. When DList
worked with 'cabal haddock' and mine didn't (when I tried to add some
asterisks), I looked at the difference between the files and sure
enough my parenthesis was on the wrong line.

BTW I highly recommend DList as a starting place for a new Haskell
project instead of hnop [2].

  Jared.

[1] http://hackage.haskell.org/package/dlist-0.5
[2] http://semantic.org/hnop/


On Wed, Aug 19, 2009 at 9:45 AM, Jared Updike <jupdike at gmail.com> wrote:
>
> I compiled and installed haddock-2.4.2 from the tarball source.
> Adding a few simple comments to the code here:
>   https://dl.getdropbox.com/u/143480/doc/DualMap.hs
> and running haddock
> $ haddock -h -o doc Data/DualMap.hs
> Warning: Data.DualMap: could not find link destinations for:
>     Data.Typeable.Typeable2 GHC.Base.Eq GHC.Show.Show GHC.Base.Ord GHC.Base.Bool Data.Set.Set
> yields:
>   https://dl.getdropbox.com/u/143480/doc/Data-DualMap.html
>
> Things look good. (Note that this module only depends on libs that ship with GHC and no other source modules.)
> However, when I try to add sections (a la http://www.haskell.org/haddock/doc/html/ch03s04.html#id289234 ) in the comments with "-- * test" I get:
> $ haddock -h -o doc Data/DualMap.hs
> Data/DualMap.hs:20:0: parse error on input `-- * test'
> haddock: Failed to create dependency graph
> I have no idea where to begin getting this to work since this error message only tells me that Haddock.Interface.depanal returned Nothing (according to a grep of the haddock sources) but not how to stop the dependency analysis from failing. Perhaps I need some more command line arguments or references to missing link destinations in GHC/base/containers documentation or some haddock config file?
> Searching Google yielded plenty of cabal build errors of the same ilk for packages on hackage but nothing about how to fix them.
>
>   Jared.