Specs:

$ cabal upgrade missingh
Resolving dependencies...
Configuring regex-base-0.93.2...
Preprocessing library regex-base-0.93.2...
Building regex-base-0.93.2...
[1 of 4] Compiling Text.Regex.Base.RegexLike ( Text/Regex/Base/RegexLike.hs, dist/build/Text/Regex/Base/RegexLike.o )
[2 of 4] Compiling Text.Regex.Base.Context ( Text/Regex/Base/Context.hs, dist/build/Text/Regex/Base/Context.o )
[3 of 4] Compiling Text.Regex.Base  ( Text/Regex/Base.hs, dist/build/Text/Regex/Base.o )
[4 of 4] Compiling Text.Regex.Base.Impl ( Text/Regex/Base/Impl.hs, dist/build/Text/Regex/Base/Impl.o )
Registering regex-base-0.93.2...
Installing library in /Users/andrew/.cabal/lib/regex-base-0.93.2/ghc-6.12.3
Registering regex-base-0.93.2...
Configuring regex-posix-0.94.4...
Preprocessing library regex-posix-0.94.4...
Building regex-posix-0.94.4...
[1 of 6] Compiling Text.Regex.Posix.Wrap ( dist/build/Text/Regex/Posix/Wrap.hs, dist/build/Text/Regex/Posix/Wrap.o )
[2 of 6] Compiling Text.Regex.Posix.String ( Text/Regex/Posix/String.hs, dist/build/Text/Regex/Posix/String.o )
[3 of 6] Compiling Text.Regex.Posix.Sequence ( Text/Regex/Posix/Sequence.hs, dist/build/Text/Regex/Posix/Sequence.o )
[4 of 6] Compiling Text.Regex.Posix.ByteString ( Text/Regex/Posix/ByteString.hs, dist/build/Text/Regex/Posix/ByteString.o )
[5 of 6] Compiling Text.Regex.Posix.ByteString.Lazy ( Text/Regex/Posix/ByteString/Lazy.hs, dist/build/Text/Regex/Posix/ByteString/Lazy.o )
[6 of 6] Compiling Text.Regex.Posix ( Text/Regex/Posix.hs, dist/build/Text/Regex/Posix.o )
Registering regex-posix-0.94.4...
Installing library in /Users/andrew/.cabal/lib/regex-posix-0.94.4/ghc-6.12.3
Registering regex-posix-0.94.4...
Configuring regex-compat-0.93.1...
Preprocessing library regex-compat-0.93.1...
Building regex-compat-0.93.1...
[1 of 1] Compiling Text.Regex       ( Text/Regex.hs, dist/build/Text/Regex.o )
Registering regex-compat-0.93.1...
Installing library in /Users/andrew/.cabal/lib/regex-compat-0.93.1/ghc-6.12.3
Registering regex-compat-0.93.1...
Configuring MissingH-1.1.0.3...
Preprocessing library MissingH-1.1.0.3...
Preprocessing executables for MissingH-1.1.0.3...
Building MissingH-1.1.0.3...
[ 1 of 47] Compiling System.Console.GetOpt.Utils ( src/System/Console/GetOpt/Utils.hs, dist/build/System/Console/GetOpt/Utils.o )
[ 2 of 47] Compiling System.Debian    ( src/System/Debian.hs, dist/build/System/Debian.o )
[ 3 of 47] Compiling System.IO.WindowsCompat ( src/System/IO/WindowsCompat.hs, dist/build/System/IO/WindowsCompat.o )
[ 4 of 47] Compiling System.Posix.Consts ( src/System/Posix/Consts.hs, dist/build/System/Posix/Consts.o )
[ 5 of 47] Compiling System.IO.StatCompat ( src/System/IO/StatCompat.hs, dist/build/System/IO/StatCompat.o )
[ 6 of 47] Compiling System.IO.PlafCompat ( src/System/IO/PlafCompat.hs, dist/build/System/IO/PlafCompat.o )
[ 7 of 47] Compiling Data.Compression.Inflate ( src/Data/Compression/Inflate.hs, dist/build/Data/Compression/Inflate.o )
[ 8 of 47] Compiling Data.Hash.MD5.Zord64_HARD ( src/Data/Hash/MD5/Zord64_HARD.lhs, dist/build/Data/Hash/MD5/Zord64_HARD.o )

src/Data/Hash/MD5/Zord64_HARD.lhs:4:2:
    Bad interface file: /Users/andrew/.cabal/lib/haskell98-1.1.0.0/ghc-6.12.3/Word.hi
        Something is amiss; requested module  haskell98:Word differs from name found in the interface file haskell98-1.1.0.0:Word
cabal: Error: some packages failed to install:
MissingH-1.1.0.3 failed during the building phase. The exception was:
ExitFailure 1

Cheers,
Andrew Pennebaker