скачал и установил iconv-1.19 в c:\iconv.
собрал package iconv-0.4.0.2 таким образом (на всякий случай добавив пути в INCLUDE и LIB):

runhaskell Setup configure --extra-include-dirs=c:\iconv\include --extra-lib-dirs=c:\iconv\lib
runhaskell Setup build
runhaskell Setup install

но ghc чего-то не находит:

C:\hs>ghc --make en.hs
Linking en.exe ...
C:\ghc\iconv-0.4.0.2\ghc-6.10.4/libHSiconv-0.4.0.2.a(Internal.o):fake:(.text+0x2196): undefined reference to `iconv_open'
C:\ghc\iconv-0.4.0.2\ghc-6.10.4/libHSiconv-0.4.0.2.a(Internal.o):fake:(.text+0x2348): undefined reference to `iconv_close'
C:\ghc\iconv-0.4.0.2\ghc-6.10.4/libHSiconv-0.4.0.2.a(Internal.o):fake:(.text+0x33f3): undefined reference to `iconv'
collect2: ld returned 1 exit status

ghci:
Prelude Main> :l en.hs
Ok, modules loaded: Main.
Prelude Main> main
Loading package bytestring-0.9.1.4 ... linking ... <interactive>: C:\ghc\i
conv-0.4.0.2\ghc-6.10.4\HSiconv-0.4.0.2.o: unknown symbol `_iconv_open'
: unable to load package `bytestring-0.9.1.4'

Prelude Main> :l eml.hs
...
Loading package iconv-0.4.0.2 ... linking ... <interactive>: C:\ghc\iconv-
0.4.0.2\ghc-6.10.4\HSiconv-0.4.0.2.o: unknown symbol `_iconv_open'
: unable to load package `iconv-0.4.0.2'

чем это лечится?