[Haskell-cafe] A new cabal odissey: cabal-1.8 breaking its own neck by updating its dependencies

[Paolo Giarrusso]

On Sat, Sep 11, 2010 at 22:29, Paolo Giarrusso <p.giarrusso at gmail.com> wrote:
> On Sat, Sep 11, 2010 at 21:43, Daniel Fischer <daniel.is.fischer at web.de> wrote:

>>> I had a broken dependency which I could see with "grep" but not
>>> otherwise.
>
>> ghc-pkg check?
>
> I tried that, but it didn't notice any breakage.

> As far as I
> understand, a package won't depend on packages which were hidden
> during its build, and all available packages will be recorded as
> dependencies in the ghc-pkg DB. Yet, for some reason this did not
> work.
Sorry for my phrasing - I was explaining my understanding of how
dependencies are discovered, but it was unclear.

I wanted to add is that I discovered this with an error similar to:

<command line>: unknown package old-locale-1.0.0.2

where the mentioned module had just been unregistered. BTW, there's no
obvious way to re-register a module because the file to pass to
ghc-pkg register is not saved on disk.

To debug it, I used cabal install -v, then I had to manually invoke
ghc -v (because cabal install didn't pass -v to ghc), then finally
used grep because the command line did not mention the offending
module.
-- 
Paolo Giarrusso - Ph.D. Student
http://www.informatik.uni-marburg.de/~pgiarrusso/