[Haskell-cafe] [ghci] unknown symbol in base-unicode-symbols- ...

Roel van Dijk vandijk.roel at gmail.com
Thu Mar 31 01:25:59 CEST 2011

I can reproduce the problem on my system with GHC-7.0.3.

The flag old-base is meant for base libraries before which
didn't export a Control.Category module. It looks like I accidentally
inverted the logic of the flag. What is weird is that is still builds
okay on my system. I would expect that, given the inverted flag logic,
Control.Category.Unicode would be missing from the installed package's
exposed module list.

I fixed the logic of the flag and the bug appears to be gone. I
uploaded the fixed version

Thanks for the bug report!

On 31 March 2011 00:05, John Obbele <john.obbele at gmail.com> wrote:
> On Wed, Mar 30, 2011 at 10:37:47PM +0200, John Obbele wrote:
>> I'm having a problem in GHCi when loading modules relying on the
>> base-unicode-symbols package. My prompt gives me the following
>> message:
>> >> ghci $
>> Loading package base-unicode-symbols- ... linking ... <interactive>: /home/john/.cabal/lib/base-unicode-symbols- unknown symbol `__stginit_basezmunicodezmsymbolszm0zi2zi1zi2_ControlziCategoryziUnicode_'
>> ghc: unable to load package `base-unicode-symbols-'
> Oki, so I'm answering to myself: the base-unicode-symbols cabal
> file introduces a quirk concerning 'base' version which hides the
> symbols in Control.Category.Unicode.
>>> base-unicode-symbols.cabal -- line 42-46
>  if !flag(old-base)
>    build-depends: base >= 3.0 && < 4.4
>  else
>    build-depends: base >= && < 4.4
>    exposed-modules: Control.Category.Unicode
> I should contact the maintainer about this …

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