current git version depends on two versions of the same library

[jgm]

What steps will reproduce the problem?

1. Clone the current git repository.
2. Try to compile it:

$ runghc Setup.hs configure --user --prefix=$HOME
Configuring pandoc-1.5.1.1...
Warning: This package indirectly depends on multiple versions of the same
package. This is highly likely to cause a compile failure.
package texmath-0.2.0.3 requires parsec-2.1.0.1
package network-2.2.1.7 requires parsec-2.1.0.1
package json-0.4.3 requires parsec-2.1.0.1
package cgi-3001.1.8.1 requires parsec-2.1.0.1
package HTTP-4000.0.9 requires parsec-2.1.0.1
package pandoc-1.5.1.1 requires parsec-3.0.1

What is the expected output? What do you see instead?

It should compile, but it doesn't. Maybe I'm doing something wrong? This is
the first Haskell program I try compiling. I had installed just the
parsec-2.1.0.1, then I installed the version 3.1.0 and tried using 'build'.
It all works fine until:

$ runghc Setup.hs build
Preprocessing library pandoc-1.5.1.1...
Preprocessing executables for pandoc-1.5.1.1...
Building pandoc-1.5.1.1...
[ 1 of 27] Compiling Text.Pandoc.XML ( src/Text/Pandoc/XML.hs,
dist/build/Text/Pandoc/XML.o )
[ 2 of 27] Compiling Text.Pandoc.CharacterReferences (
src/Text/Pandoc/CharacterReferences.hs,
dist/build/Text/Pandoc/CharacterReferences.o )
[ 3 of 27] Compiling Text.Pandoc.Blocks ( src/Text/Pandoc/Blocks.hs,
dist/build/Text/Pandoc/Blocks.o )
[ 4 of 27] Compiling Paths_pandoc ( dist/build/autogen/Paths_pandoc.hs,
dist/build/Paths_pandoc.o )
[ 5 of 27] Compiling Text.Pandoc.ODT ( src/Text/Pandoc/ODT.hs,
dist/build/Text/Pandoc/ODT.o )
[ 6 of 27] Compiling Text.Pandoc.Definition (
src/Text/Pandoc/Definition.hs, dist/build/Text/Pandoc/Definition.o )
[ 7 of 27] Compiling Text.Pandoc.Shared ( src/Text/Pandoc/Shared.hs,
dist/build/Text/Pandoc/Shared.o )
[ 8 of 27] Compiling Text.Pandoc.Templates ( src/Text/Pandoc/Templates.hs,
dist/build/Text/Pandoc/Templates.o )
[ 9 of 27] Compiling Text.Pandoc.Readers.RST (
src/Text/Pandoc/Readers/RST.hs, dist/build/Text/Pandoc/Readers/RST.o )
[10 of 27] Compiling Text.Pandoc.Readers.LaTeX (
src/Text/Pandoc/Readers/LaTeX.hs, dist/build/Text/Pandoc/Readers/LaTeX.o )
[11 of 27] Compiling Text.Pandoc.Readers.HTML (
src/Text/Pandoc/Readers/HTML.hs, dist/build/Text/Pandoc/Readers/HTML.o )
[12 of 27] Compiling Text.Pandoc.Readers.Markdown (
src/Text/Pandoc/Readers/Markdown.hs,
dist/build/Text/Pandoc/Readers/Markdown.o )
[13 of 27] Compiling Text.Pandoc.Writers.Markdown (
src/Text/Pandoc/Writers/Markdown.hs,
dist/build/Text/Pandoc/Writers/Markdown.o )
[14 of 27] Compiling Text.Pandoc.Writers.RST (
src/Text/Pandoc/Writers/RST.hs, dist/build/Text/Pandoc/Writers/RST.o )
[15 of 27] Compiling Text.Pandoc.Writers.LaTeX (
src/Text/Pandoc/Writers/LaTeX.hs, dist/build/Text/Pandoc/Writers/LaTeX.o )
[16 of 27] Compiling Text.Pandoc.Writers.ConTeXt (
src/Text/Pandoc/Writers/ConTeXt.hs, dist/build/Text/Pandoc/Writers/ConTeXt.o )
[17 of 27] Compiling Text.Pandoc.Writers.MediaWiki (
src/Text/Pandoc/Writers/MediaWiki.hs,
dist/build/Text/Pandoc/Writers/MediaWiki.o )
[18 of 27] Compiling Text.Pandoc.Highlighting (
src/Text/Pandoc/Highlighting.hs, dist/build/Text/Pandoc/Highlighting.o )
[19 of 27] Compiling Text.Pandoc.Readers.TeXMath (
src/Text/Pandoc/Readers/TeXMath.hs, dist/build/Text/Pandoc/Readers/TeXMath.o )

src/Text/Pandoc/Readers/TeXMath.hs:50:30:
Couldn't match expected type Text.Parsec.Prim.Parsec s () a' against inferred type parsec-2.1.0.1:Text.ParserCombinators.Parsec.Prim.GenParser
Char st [Exp]'
In the first argument of parse', namelyformula'
In the expression: parse formula "formula" inp
In the expression:
case parse formula "formula" inp of {
Left _ -> Just [Str inp]
Right exps -> expsToInlines exps }

What version of the product are you using? On what operating system?

It is all current, as far as I know:

$ runghc --version
runghc 6.12.1

Google Code Info:
Issue #: 236
Author: bike...@gmail.com
Created On: 2010-05-05T21:50:54.000Z
Closed On: 2010-05-06T01:55:50.000Z

[jgm]

oops, I forgot:

$ uname -a
Linux mnesala 2.6.30-2-686 #1 SMP Fri Dec 4 00:53:20 UTC 2009 i686 GNU/Linux

thanks in advance!

Google Code Info:
Author: bike...@gmail.com
Created On: 2010-05-05T21:52:48.000Z

[jgm]

Try:

runghc Setup.hs configure --user --prefix=$HOME --constraint 'parsec < 3'

Or, just "cabal install". The cabal tool has an automatic 'parsec < 3' constraint.
Let me know if this helps.

Google Code Info:
Author: fiddloso...@gmail.com
Created On: 2010-05-05T22:30:45.000Z

[jgm]

Yep, it compiled without any errors now! Thanks again!

Google Code Info:
Author: bike...@gmail.com
Created On: 2010-05-06T00:42:56.000Z

[jgm]

Google Code Info:
Author: fiddloso...@gmail.com
Created On: 2010-05-06T01:55:50.000Z