15 Jun
                
                    2012
                
            
            
                15 Jun
                
                '12
                
            
            
            
        
    
                2:37 p.m.
            
        Am I doing something wrong here?
Well, you're using ghc-6.12 ... :-) The most recent version of pandoc that Hackage claims to have built with ghc 6.12 looks to be 1.6. Rolling back that far eliminates the json dependency entirely, so I think it would solve your issue. Or you could use the Pandoc in Debian stable, which appears to be 1.5.1. A more recent ghc would probably also work, of course, but I imagine you're trying the Debian stable version for a reason.