Resolved my problems by going after later versions of ByteString:

cabal install bytestring-0.9.2.0

Resolving dependencies... cabal: bytestring.cabal:70: The 'type' field is required for test suites. The available test types are: exitcode-stdio-1.0 cabal: Error: some packages failed to install: bytestring-0.9.2.0 failed during the configure step. The exception was: ExitFailure 1 That did not work, but the following:

cabal install bytestring-0.9.1.10

Resolving dependencies... No packages to be installed. All the requested packages are already installed. If you want to reinstall anyway then use the --reinstall flag. tells me that I already had a working version. I was chasing the wrong problem. Looking at my BlazeHtml code again, there were imports declared as follows:

import Prelude hiding (head, id, div)

import Text.Blaze.Html4.Strict as H hiding (map)

import Text.Blaze.Html4.Strict.Attributes as A

import Control.Monad

import Data.Monoid (Monoid, mappend, mempty, mconcat)

import Text.Blaze.Renderer.Utf8 (renderHtml)

import Data.ByteString.UTF8 as B

The last import was the problem. Something changed in the libraries to make this 'UTF8' line break. I worked around this for now. Need to research some more, quick glance at the bytestring library versions suggest 'Char8' not 'UTF8' . However Data.ByteString.UTF8 is in the utf8-string-0.3 library (http://hackage.haskell.org/packages/archive/utf8-string/0.3/doc/html/Data-B yteString-UTF8.html). So my question becomes "Can someone tell me if there are notes somewhere on the state of play of the UTF8 ByteString Libraries" Ralph Hodgson, http://twitter.com/ralphtq @ralphtq From: haskell-cafe-bounces@haskell.org [mailto:haskell-cafe-bounces@haskell.org] On Behalf Of Ralph Hodgson Sent: Saturday, October 01, 2011 8:31 PM To: haskell-cafe@haskell.org Subject: [Haskell-cafe] ByteString install issues with GHC 7.0.3 on Windows 7 This morning I was successfully running BlazeHtml on Windows 7. Then I installed some libraries from other packages and BlazeHtml broke. I then decided to go from ghc 6.12.1 to ghc 7.0.3 and reinstall everything. BlazeHtml installed OK. But my program also needed ByteString. So I did the following: First I tried the stable version:

cabal install bytestring-0.9.1.4

Resolving dependencies... Configuring bytestring-0.9.1.4... Preprocessing library bytestring-0.9.1.4... Building bytestring-0.9.1.4... Data\ByteString.hs:3:24: Cannot parse LANGUAGE pragma Expecting comma-separated list of language options, each starting with a capital letter E.g. {-# LANGUAGE RecordPuns, Generics #-} cabal: Error: some packages failed to install: bytestring-0.9.1.4 failed during the building phase. The exception was: ExitFailure 1 I am not experienced enough to fix this, so I tried a previous ByteString version:

cabal install bytestring-0.9.1.3

Resolving dependencies... Configuring bytestring-0.9.1.3... Preprocessing library bytestring-0.9.1.3... Building bytestring-0.9.1.3... [1 of 8] Compiling Data.ByteString.Fusion ( Data\ByteString\Fusion.hs, dist\buil d\Data\ByteString\Fusion.o ) [2 of 8] Compiling Data.ByteString.Internal ( Data\ByteString\Internal.hs, dist\ build\Data\ByteString\Internal.o ) Data\ByteString\Internal.hs:79:42: Module `GHC.IOBase' does not export `RawBuffer' cabal: Error: some packages failed to install: bytestring-0.9.1.3 failed during the building phase. The exception was: ExitFailure 1 No joy. Help appreciated. May try all this on my MAC tomorrow. Ralph Hodgson, http://twitter.com/ralphtq @ralphtq Mobile Phone: +1 781-789-1664