I had to use two Haskell Platforms at once in the Windows environment. We use Haskell Platform 2011.1 as our main build platform. It provide real benefits for code with GADTs so we ported most of our code there. Right now we cannot switch back or it would be quite a regress. We also have some heavy type level computation code in one of our programs so we have to use Haskell Platform 2010.2 with ghc 6.12.3 as 7.0.2 is quite slow at that. And now I have some strange error (it didn't appear when I used only one of Haskell platforms): ---------------------------------- ghc-6.12.3 -O2 -odir objs -hidir objs -stubdir objs -o CGen.exe -fcontext-stack=100 --make CGen.hs Linking CGen.exe ... realgcc.exe: USERNA: Invalid argument C:\PROGRA~1\HASKEL~1\201020~1.0\lib\..\mingw\bin\windres: "C:\PROGRA~1\HASKEL~1\ 201020~1.0\lib\..\mingw\bin\gcc exited with status 1 ---------------------------------- When I looked at the dump in hex, I encountered that "USERNA" string contains "USERNAM^H" byte sequence, actually. I cannot look at ghc -v5 as I get another error: ---------------------------------- Glasgow Haskell Compiler, Version 6.12.3, for Haskell 98, stage 2 booted by GHC version 6.10.4 Using binary package database: C:\PROGRA~1\HASKEL~1\201020~1.0\lib\package.conf.d\package.cache ... ... (I deleted much of the lines) ... Deleting: *** Deleting temp dirs: Deleting: <stderr>: hPutChar: invalid argument (character is not in the code page) ---------------------------------- I use localized version of Windows XP so it appears that ghc cannot print some name with russian characters in it. And here I stuck. I cannot find source of one error because of another error. Could anyone help me?